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Adult Obesity: An Overview

5 Contact Hours including 5 Advanced Pharmacology Hours
This peer reviewed course is applicable for the following professions:
Advanced Practice Registered Nurse (APRN), Certified Nurse Midwife, Certified Nurse Practitioner, Certified Registered Nurse Anesthetist (CRNA), Clinical Nurse Specialist (CNS), Licensed Practical Nurse (LPN), Licensed Vocational Nurses (LVN), Midwife (MW), Nursing Student, Registered Nurse (RN)
This course will be updated or discontinued on or before Friday, April 26, 2024

Nationally Accredited

CEUFast, Inc. is accredited as a provider of nursing continuing professional development by the American Nurses Credentialing Center's Commission on Accreditation. ANCC Provider number #P0274.


Outcomes

To provide an overview of obesity and explain the healthcare professional's role in preventing and treating obesity.

Objectives

After completing this course, the participant will be able to meet the following 9 objectives:

  1. Recognize the incidence and prevalence of obesity in the US.
  2. Define obesity.
  3. Describe the classification of overweight and obese via the Body Mass Index (BMI).
  4. Relate the measures for determining body fat, i.e., the circumference of the abdomen, waist circumference, waist-to-hip ratio, and neck circumference.
  5. Describe the possible causes of obesity.
  6. Differentiate between the negative implications of being obese and the positive benefits of weight loss.
  7. Describe the assessment of a patient in terms of health history and physical examination leading to the diagnosis of obesity.
  8. Describe the management of obese patients in terms of behavioral therapy, dietary changes, increased physical activity, medications, and surgery.
  9. Describe follow-up for the obese patient in terms of behavioral therapy, dietary changes, increased physical activity, medications, and surgery.
CEUFast Inc. and the course planners for this educational activity do not have any relevant financial relationship(s) to disclose with ineligible companies whose primary business is producing, marketing, selling, re-selling, or distributing healthcare products used by or on patients.

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To earn of certificate of completion you have one of two options:
  1. Take test and pass with a score of at least 80%
  2. Reflect on practice impact by completing self-reflection, self-assessment and course evaluation.
    (NOTE: Some approval agencies and organizations require you to take a test and self reflection is NOT an option.)
Author:    Raymond Lengel (MSN, FNP-BC, RN)

Introduction

Greater than 40% of the adult population in the United States (US) is obese. Obesity increased from 15% in the late 1970s to 42.4% in 2018 (Center for Disease Control [CDC], 2021a). Non-Hispanic blacks have an obesity rate of 49.6%, Hispanic adults have an obesity rate of 44.8%, non-Hispanic whites have an obesity rate of 42.2%, while non-Hispanic Asian adults have an obesity rate of 17.4% (CDC, 2021a). In 1991, only four states had obesity rates greater than 15%. In 2020, only three states and the District of Columbia had obesity rates of less than 25% (CDC, 2021a).

Obesity is not a cheap disease. It is estimated that obesity costs the US 147 billion dollars a year, and the annual medical costs for obese individuals are 1,429 dollars higher than those who have normal body weight (CDC, 2021a).

The Obesity Epidemic

Our culture is centered around food. Most social events revolve around food. High-caloric foods can be found in most workplaces, and a fast-food restaurant is on almost every corner. While fast food is not the primary determinate of obesity, personal choices contribute to obesity. A hamburger, small fries, and diet soda meal is about 500 calories. Unfortunately, a more typical meal includes a double cheeseburger, large fries, and a large soda, which equals 1,450 calories.

Obesity is just not for adults. Children are obese as well. The generation of children raised today may have shorter life spans than their parents as childhood obesity rates are increased over previous years (CDC, 2021b). Children eat poorly, a habit that results from their parents, the previous generation, and society. Obesity is a form of malnutrition.

Definitions

Being overweight or obese is being at a weight that is more than what is considered healthy. It increases the risk of many diseases, reduces the quality of life, and increases the risk of death (CDC, 2021b). The classification of being overweight and obese is determined by using weight and height to calculate the body mass index (BMI), which healthcare providers use to define the risk of body weight. Generally, for adults, the BMI correlates with the amount of body fat. It is not a perfect system, as it does not directly measure body fat. For an individual with a large amount of muscle mass, the equation will overestimate the amount of fat, and this equation will underestimate body fat for those with significant muscle wasting. The BMI utilizes a mathematical formula to classify patients as underweight, normal body weight, overweight and obese. Obesity is defined as having a BMI of thirty or higher, and BMI is determined by dividing the weight in kilograms by the height in meters squared (Table 1).

Table 1: Body Mass Index
Interpretation of Body Mass Index
UnderweightLess than 18.6
Normal18.6-24.9
Overweight25-29.9
Obese30 or more
Morbidly Obese40 or more

Case Study 1

John, a 42 year-old man, weighs 200 pounds or 90.9 kilograms and is 5 feet 9 inches tall or 1.75 meters. His waist measures 35 inches, and his hips measure 33 inches, and his neck measures 15.5 inches.

What is his BMI? What is his waist to hip ratio?

To determine his BMI use the following formula:

  • Weight in kilograms/(height in meters x height in meters)
  • Answer: 90.9/(1.75 x 1.75)=29.7

John has a BMI of 29.7, which places him in the overweight category.

His waist-to-hip ratio is calculated by dividing 35/33, which equals 1.06. This calculation places him at high risk as it is above 0.9. John has the typical apple shape indicating he has abdominal obesity linked to many adverse health effects, including diabetes, HTN and dyslipidemia.

The following are online BMI tools:

Measures for Determining Body Fat

More sophisticated measures of body fat exist, but there is no data to show where death and disability rates are increased with anything other than the BMI. Abdominal obesity is the most harmful type of fat, and measuring the amount of fat in the abdomen is essential for determining the risk of excess body fat. Fat on the trunk is more problematic than fat on the legs, arms, or hips. Fat around the waist is more biologically active, and it secretes inflammatory proteins and is linked to plaque deposits in the coronary arteries (Engin, 2017).

The measurement of abdominal obesity can be done in several ways. The most precise way is to image the trunk using magnetic resonance imaging (MRI), which accurately measures intra-abdominal fat, but this is impractical in most settings as it is costly. A more common way to determine the degree of abdominal obesity is by measuring the circumference of the abdomen. A waist circumference of greater than 40 inches in men and 35 inches in women is associated with increased disease risk (National Institute of Health {NIH}, n.d.).

The waist-to-hip ratio is another way to determine risk. The number is obtained by dividing the waist circumference by the hip circumference. If the waist-to-hip ratio is greater than 0.9 in men or 0.8 in women, the patient is at increased risk for obesity-related complications (NIH, n.d.).

Those with a large waist-to-hip ratio are said to have an "apple shape," which describes a situation when there is more weight in the abdomen, and a "pear" shape is when there is more weight in the hips. Apple shapes are at higher risk for hypertension (HTN), heart disease, and diabetes than pear shapes (CDC, 2021b).

Neck circumference should also be evaluated as it predicts obesity and sleep apnea. Those with neck circumferences of greater than 36 cm in diabetics and 37 cm in non-diabetics are likely to suffer from central obesity (Tom et al., 2018). Men with a neck circumference greater than 17 inches and women with a neck circumference greater than 16 inches are at risk for sleep apnea (CDC, 2021b).

Cause of Obesity

Energy intake is simply the amount of energy put in the body in food and drink. When energy intake is greater than energy output, the body stores the extra energy as fat. The amount of energy an individual expends per day depends on multiple factors, including age, sex, amount of muscle mass, genetic factors, existing disease states, ambient temperature, and activity level.

One pound of energy is equal to 3,500 calories. An excess of 3,500 calories needs to be consumed to gain one pound of fat, assuming everything else stays stable. For example, if someone has had a stable weight for over one year and then adds a new routine of eating one cookie, which is equivalent to 100 calories, then in 35 days, that individual would gain one pound.

Many societal factors are strongly related to obesity. Long-work schedules keep people away from active lifestyles. Large portion sizes are the norm at many restaurants and encourage overeating, thus increasing calorie intake. Lack of access to healthy food and easy access to junk food is another factor. Many workplaces have vending machines with chips, candy bars, and sodas. Sporting events have snack bars with foods like nachos, popcorn, beer, and soda instead of healthier options. The abundance of high-caloric food is typical at restaurants, workplaces, parties, and many homes.

Many Americans are sedentary, and many people are more involved with spectator sports than participating in sports. Extra calories consumed that are not expended are stored as fat.

Chronic sleep deprivation may promote weight gain due to its effects on physiology and behavior (St-Onge, 2017). In addition to weight gain, sleep deprivation is associated with adverse cardiovascular events, glucose intolerance, and decreased leptin levels (St-Onge, 2017). Leptin is a hunger-suppressing hormone that signals satiety to the hypothalamus and reduces fat storage and energy intake. In addition to the effects of leptin, sleep-deprived individuals are awake and have more opportunities to eat, often at night in front of the television.

Genetics are also related to obesity. Genes have a strong influence on the propensity to be overweight or obese and affect the location and the amount of fat stored. Dopamine, a brain chemical that helps make eating and other behaviors more rewarding, is related to food consumption and may be genetically lower in some individuals (Goodarzi, 2018).

Families also share food and activity habits, which link the environment to weight. Parents who have an abundance of fruits and vegetables in the house and minimal high-calorie junk food tend to have children who eat better than in a household with an abundance of chips, doughnuts, and ice cream.

Certain health conditions increase the incidence of obesity. Hypothyroidism, Cushing's disease, depression, and polycystic ovarian syndrome increase the chance of obesity. Medications such as selective serotonin reuptake inhibitors, antidepressants, tricyclic antidepressants, antipsychotics, some anticonvulsants, lithium, insulin, sulfonylureas, and corticosteroids increase the incidence of weight gain (Perreault & Bessesen, 2022).

Negative Implications of Obesity

Obesity is associated with increased mortality and morbidity, and the risk of disease increases with increasing BMI and abdominal fat levels. The cut-off for normal body weight is a BMI of 25.0 kg/m2, and when the number exceeds 30 kg/m2, the risk is significantly increased (CDC, 2021b).

Obesity increases the risk of heart disease, stroke (CVA), HTN, and abnormal cholesterol (CDC, 2021b). Obesity is associated with an increased risk of cardiovascular disease, at least partly because of the worsening effect on its risk factors: dyslipidemia and HTN, but there is an independent effect of obesity on heart disease (CDC, 2021b).

CVAs are more common in obese patients, and many of the same risk factors associated with heart disease are related to CVAs. HTN, abnormal cholesterol, blood clotting, and glucose intolerance are why CVA rates are higher in obese individuals (CDC, 2021b).

Obesity increases the risk for type II diabetes (CDC, 2021b). Obesity does this by decreasing the body's ability to use insulin in a condition called insulin resistance. Insulin, a hormone produced by the pancreas, is used to help transport the sugar that circulates in the blood into the cells. As insulin resistance does not optimally allow the glucose to enter the cells, blood glucose levels rise. This increased blood sugar due to insulin resistance signals the brain that glucose is not getting into the cells. The brain responds by releasing more insulin and glucose, thereby increasing the amount of glucose and insulin in the blood.

Insulin resistance is common in obese individuals and strongly correlates with abdominal fat instead of fat stored in the legs and hips. High insulin and sugar levels in the blood have toxic effects on many body systems, including the eyes, heart, nerves, and kidneys. Insulin resistance is associated with increased risk for blood clotting, which increases vascular disease risk, including heart attacks (MIs) and CVAs.

Not only does obesity tax the heart and hormonal system, but also it negatively affects other body systems. Excess body weight puts stress on the joints and increases the risk, incidence, and severity of osteoarthritis (CDC, 2021b). Obesity is associated with functional impairments, such as being unable to bend over to pick up an item off the floor, and negatively impacts the quality of life. Obesity increases the incidence of gout, with the risk being higher in those who are heavier (CDC, 2021b).

Obese individuals have increased gallbladder disease, gastroesophageal reflux, erosive esophagitis, and esophageal cancer. Gastrointestinal reflux disease (GERD) symptoms are correlated with BMI, and gallstones and gallbladder disease are more common in overweight and obese individuals (CDC, 2021b).

Non-alcoholic fatty liver disease is another complication of obesity and presents with damage to the liver that resembles alcohol damage but in the absence of alcohol abuse. It is often associated with metabolic syndrome and insulin resistance. Weight loss typically improves insulin resistance and non-alcoholic fatty liver (Armandi & Schattenberg, 2021).

Obesity also increases the incidence of endometrial, esophageal, renal, and pancreatic adenocarcinomas, hepatocellular carcinoma, gastric cardia cancer, meningioma, multiple myeloma, colorectal cancer, postmenopausal breast cancer, ovarian cancer, gallbladder cancer, and thyroid cancer (Avgerinos et al., 2019).

Other conditions are associated with obesity. Obesity significantly increases the risk for sleep apnea as fat stored around the neck impedes breathing. Obesity weakens the immune system and makes it harder for obese patients to fight infections. Stress incontinence, urine leaking during sneezing, laughing, or coughing, is associated with obesity (CDC, 2021b).

Surgery is riskier in obese individuals than in those of normal weight. The obese patient has greater surgical risk and more postoperative complications, such as delayed wound healing, infection, deep venous thrombosis (DVT), pulmonary embolism (PE), and pneumonia (Goyal et al., 2019 & CDC, 2021b).

Obesity affects mood, with abdominal obesity significantly increasing the risk of depression and anxiety. Depression and obesity feed off one another. Depression lowers self-esteem and makes weight loss harder (Fulton et al., 2021).

Table 2 – Diseases Associated with Obesity
  • Anxiety
  • Depression
  • Dyslipidemia
  • Gallbladder disease
  • Gastrointestinal reflux disease (GERD)
  • Glucose intolerance, insulin resistance, and diabetes
  • Gout
  • Heart disease
  • Heart failure
  • Hypertension (HTN)
  • Increased risk of certain cancers
  • Non-alcoholic fatty liver disease
  • Obstructive sleep apnea
  • Osteoarthritis
  • Stroke (CVA)

Positive Benefits of Weight Loss

To combat the negative impact of obesity, individuals need to lose weight or maintain a healthy weight. Weight loss can be accomplished through diet and lifestyle modifications, including exercise, medication, or surgery. Not everyone needs to lose weight. If the BMI is in the ideal range, maintenance of that body weight along with eating a well-balanced diet will help maintain good health. Maintaining optimal body weight is not the only factor in good health. Many alcohol abusers have an ideal body weight but have poor nutritional status. Eating a healthy diet and maintaining an optimal body weight are keys to staving off illness and preventing functional decline.

Weight loss is associated with decreased blood pressure, improved insulin sensitivity, increased high-density lipoprotein levels, and decreased triglycerides. Loss of excessive body weight will reduce strain on the joints and improve osteoarthritis symptoms. Weight loss can uplift spirits, improve mood, reduce depression/anxiety, and reduce the incidence of GERD and gallbladder disease. Weight loss improves the quality of life and should increase life expectancy (Perreault & Bessesen, 2022 & CDC, 2021b).

Patient Assessment

The healthcare system does a poor job in the evaluation of obesity. The way healthcare professionals think about obesity and how the system is set up needs to change to more effectively handle this problem. Healthcare professionals typically tell patients they need to lose weight but do not discuss strategies or make referrals for success. A system needs to be built that will help healthcare professionals more efficiently address and get reimbursed for the treatment of obesity.

The first aspect of evaluating obesity should be a complete health history. The health history should be reviewed to determine what diseases might be causing, contributing to, or complicating obesity. Important diseases include depression, eating disorders, and endocrine disease. Evaluation of all comorbidities is part of the patient's health history. A complete dietary history is helpful. This history should be done with the help of a registered dietitian. Evaluating body weight changes, lifestyle habits, and exercise patterns are essential.

Assessment of obesity includes evaluation of height and weight and determining the BMI. The patient should be classified into one of the categories for body weight (see Table 1 above). It is also essential to get an abdominal circumference and a waist-to-hip ratio. The neck circumference should be measured to determine the risk for sleep apnea.

The skin should be examined. Hirsutism is defined as excessive or increased hair growth where it typically does not occur. In women, hirsutism may indicate polycystic ovarian disease. Intertriginous rashes may be a complication of obesity. Acanthosis nigricans, characterized by thick, dark, velvety skin often on the neck or in the armpits, may point to insulin resistance.

The heart and lung assessment should look for HTN, cardiomegaly, or respiratory disease abnormalities. The abdomen should be evaluated for an enlarged liver, possibly suggesting non-alcoholic fatty liver disease. When examining the extremities, search for joint deformities, evidence of osteoarthritis, and any pressure ulcers.

After obesity is diagnosed and quantified, the healthcare professional needs to consider possible causes of obesity. Is there a disease present? Is there a medication contributing to the disease? Or is it a lifestyle issue?

Diseases that need to be considered include hypothyroidism, Cushing syndrome, and eating disorders such as binge eating disorder, depression, and anxiety. Rare genetic disorders may be related to obesity, such as Turner's syndrome or Prader-Willi syndrome.

Complications of obesity should be considered. Complications often associated with obesity include heart disease, HTN, dyslipidemia, diabetes, sleep apnea, GERD, gallbladder disease, and non-alcoholic fatty liver disease.

The patient's motivation to lose weight should be part of the evaluation. Determining why weight loss is desired can help the healthcare professional understand which interventions would be helpful and how aggressive treatment should be. A history of previous weight loss attempts can help determine the most effective treatment. Determining how much time the patient will devote to weight loss will help determine which plan would be most helpful in the treatment of the disease. Does the patient work a 70-hour work schedule, or do they sit around the house all day watching television? It is helpful to determine if the patient has a support network of family and friends. Ensure that the patient understands the prescribed weight loss plan's risks, benefits, and expectations.

Treatment

Treatment should be initiated with a BMI above 25 if there are two or more of the following risk factors:

  • Dyslipidemia
  • Family history of diabetes or heart disease
  • HTN
  • Large waist circumference

If the BMI is greater than 30, treatment should be initiated regardless of the number of risk factors. Irrespective of weight or risk factors, all people should be encouraged to live a healthy lifestyle.

Goals of weight loss should include a:

  • Gradual reduction in body weight that can be maintained over the long term
  • Reduction in risk factors

Weight loss of one to two pounds a week is ideal. Individual goals, motivation, and medical comorbidities need to be considered when setting goals.

Treatment options include one or more of the following:

  • Dietary changes
  • Increased physical activity
  • Medications
  • Surgery
  • Behavior therapy

Dietary Changes

Weight loss will occur if an individual finds a lifestyle that expends more calories than it consumes. As long as the individual sticks to the lifestyle changes, weight loss will occur. A big problem with dieting is that individuals do not comply with this strategy over the long term. Fad diets are readily available, and many are effective as long as the individual adheres to fewer calories in and more calories out.

Dietary changes are a cornerstone of an effective weight loss program. Reducing the number of calories consumed to less than the number of calories expended creates a negative caloric balance and weight loss. While it goes against the norm in American culture, where individuals want immediate gratification, the ideal weight loss program should include eating a healthy diet that would result in a slow and steady weight loss while improving the diet's nutritional content.

Many diets are available for weight loss, including low-calorie, low fat, low-carbohydrate, balanced, and many fad diets. Most diets have some proven efficacy, at least in the short term. Low-caloric diets are between 800 to 1,200 calories per day, while normal-caloric diets are greater than 1,200 calories. Normal caloric diets will not induce a rapid weight loss, but they allow the individual to develop a healthy eating pattern while losing weight. Very-low caloric diets, often less than 800 calories per day, typically involve specialized foods or drinks that do not teach skills necessary for the maintenance stage of the weight loss.

Healthy Normal-Calorie Diet

Nutritional status has an immense impact on weight, health, disease progression, and patient healing. Good diets incorporate various foods and are composed of many fruits and vegetables, whole grains, and lean meats. A proper balance of carbohydrates, proteins, and fats is crucial in a healthy diet. A normal-caloric diet focuses on eating healthy foods to maintain an optimal weight while creating a negative caloric balance.

Below are key features of the Dietary Guidelines for Americans 2020-25 (US Department of Agriculture and U. S. Department of Health and Human Services, 2020):

  • Follow a healthy eating pattern across the lifespan. All food and beverage choices matter. Choose a healthy eating pattern at an appropriate caloric level to help achieve and maintain a healthy body weight, support nutrient adequacy, and reduce the risk of chronic disease.
  • Focus on variety, nutrient density, and amount. To meet nutrient needs within caloric limits, choose various nutrient-dense foods across and within all food groups in recommended amounts.
  • Limit calories from added sugars and saturated fats and reduce sodium intake. Reduce intake of foods and beverages higher in these components.
  • Shift to healthier food and beverage choices. Choose nutrient-dense foods and beverages across and within all food groups in place of less healthy choices. Consider cultural and personal preferences to make these shifts easier to accomplish and maintain.
  • Support healthy eating patterns for all. Everyone has a role in helping to create and support healthy eating patterns in multiple settings nationwide, from home to school to work to communities.
  • The guidelines recommend eating various fresh fruits and vegetables, whole grains, low-fat proteins, and healthy fats. The guidelines recommend reducing total energy intake while maintaining nutrient intake and increasing physical activity for weight loss.

A healthy eating pattern includes:

  • A variety of vegetables from all the subgroups - dark green, red, and orange, legumes (beans and peas), starchy, and other
  • Fat-free or low-fat dairy, including milk, yogurt, cheese, and fortified soy beverages
  • Fruits, especially whole fruits
  • Grains, at least half of which are whole grains
  • Healthy oils
  • Protein foods, including seafood, lean meats and poultry, eggs, legumes (beans and peas), and nuts, seeds, and soy products
  • A healthy eating pattern includes certain limitations on food (US Department of Agriculture and U. S. Department of Health and Human Services, 2020):
    • Consume less than 10% of calories per day from added sugars
    • Consume less than 10% of calories per day from saturated fats
    • Consume less than 2,300 milligrams per day of sodium
    • If alcohol is consumed, it should be consumed in moderation - up to one drink per day for women and up to two drinks per day for men - and only by adults of legal drinking age.

Healthy eating patterns are associated with positive health outcomes. Strong evidence shows that healthy eating patterns are associated with a reduced risk of cardiovascular disease (CVD) (Perreault & Bessesen, 2022). Moderate evidence indicates that healthy eating patterns are also associated with a reduced risk of type 2 diabetes, certain types of cancers (such as colorectal and postmenopausal breast cancers), overweight, and obesity (USDA, 2015). Emerging evidence suggests relationships between eating patterns, neurocognitive disorders, and congenital anomalies (USDA, 2015).

Carbohydrates should constitute 45% - 65% of total calories. Not all carbohydrates are created equal. Foods high in simple carbohydrates, including white bread, white rice, ice cream, candy, soda, and jellies, are absorbed quickly and cause a rapid rise in blood sugar. Simple carbohydrates are not packed with essential vitamins, minerals, and healthy chemicals like complex carbohydrates. Complex carbohydrates include whole-grain cereals, beans, and many vegetables that are more densely packed with vitamins, minerals, and fibers. The bulk of a healthy diet should be consumed from complex carbohydrates, including fruits, vegetables, and whole grains.

Fiber, another carbohydrate, is an essential food element to prevent disease. It is recommended that 14 grams of fiber are eaten for every 1,000 calories consumed, which equates to approximately 25 grams of fiber per day for women and 38 grams a day for men (Quagliani & Felt-Gunderson, 2016). Interestingly, Americans only eat 15 grams of fiber a day (US Department of Agriculture and U. S. Department of Health and Human Services, 2020). Fiber is found in fresh fruits and vegetables, bran cereals, and beans. Eating a diet high in fiber has multiple benefits, including preventing constipation, possibly reducing the risk of colon cancer, aiding in weight loss, improving cholesterol readings, and slowing the absorption of sugars (USDA, 2015).

Adults should eat 46 – 56 grams of protein or 0.8 grams/kg of ideal body weight per day (Kim, 2021). While many people advocate a high protein diet, this does not result in greater weight loss than a moderate protein level. Some experts suggest that a diet high in protein results in more satiety and leads to increased compliance with a low-calorie diet. High protein levels can put extra strain on the kidneys (Kim, 2021).

Saturated fat should make up less than 10% of the total calories in the diet (Kim, 2021). Partially hydrogenated fats as found in margarine, crackers, cookies, doughnuts, and chips are particularly harmful to the body's cholesterol. Monounsaturated fats, polyunsaturated fats, and omega-3 fats should be substituted for saturated fats. Monounsaturated fats are in avocado, olive, canola, and peanut oils. Polyunsaturated fats are not as healthy as monounsaturated fats but are better than saturated fats and are prevalent in soybean and corn oil. Omega-3 fats are found in certain fish, including mackerel, salmon, and albacore tuna.

Water is essential to life. The US National Academies of Sciences, Engineering, and Medicine (2004) recommends 15.5 cups of fluid for men and 11.5 cups of fluid each day for women. Benefits of drinking water include less constipation, reduced fluid retention, and flushing the body of unnecessary substances. Those who drink water before meals often eat less during the meal. In addition, cold water may increase weight loss by elevating energy expenditure.

Small quantities of bad food are not necessarily harmful but should be avoided in large amounts. Foods that should be avoided in large quantities include foods high in sugar and empty in calories, high in trans-fat, and high in saturated fat. Foods high in sugar and empty in calories include candy and regular soft drinks. Trans fat is found in many processed foods such as chips, cookies, and crackers. Saturated fats are found in fatty red meats, butter, and fried food.

Medically Supervised Diets

Structured diets under the supervision of healthcare professionals are another trend in today's weight loss armamentarium. These diets are typically very low calories (less than 800 calories per day) and offer rapid weight loss (Kim, 2021). Because these diets are so low in calories, they are risks. Loss of lean mass is common and can be combated by adding a resistance-training program. Gallstone formation, electrolyte imbalance, and dehydration are risks and are the main reasons they are medically supervised. Other low-calorie diets risks include hair loss, hypothermia, and skin thinning (Muscogiuri, 2019).

The popularity of very-low-caloric ketogenic diets (VLCKD) has been demonstrated in the last few years. It has been shown as a successful method to manage obesity, as it provides rapid weight loss, which provides a psychological boost and improves compliance. It also preserves lean mass, which is critical to glucose metabolism (Muscogiuri et al., 2019).

Multiple factors need to be considered when evaluating very-low-calorie diets. Initial weight loss in these diets is often high because of water and muscle mass loss, which will stabilize after a short period. Men tend to lose more weight partly because they have more muscle mass.

Low-Carbohydrate Diets

Low-carbohydrate diets are one of the more popular diet methods, and they work well. Low carbohydrate diets typically include between 50 - 130 grams of carbohydrates per day. Ketosis may occur when carbohydrates are less than 20 - 50 grams per day (Kim, 2021). Ketosis results in significant weight loss, but the weight loss consists of significant water and lean tissue loss.

Unfortunately, many questions remain unanswered, especially concerning low carbohydrate diets' long-term safety and efficacy. Low carbohydrate diets typically incorporate high protein animal foods, usually high in saturated fat. This diet theoretically increases the risk of CAD, diabetes, CVA, and several types of cancer. Excessive protein intake increases the risk of osteoporosis and kidney and liver disorders (Kim, 2021).

Considering the energy in/energy out equation that explains weight loss, low carbohydrate diets that restrict calories will result in weight loss. Some data points to the low carbohydrate diet as slightly better in weight loss, at least in the first 6 - 12 months. Shai et al. (2008) compared a low-fat diet that restricted calories, a Mediterranean diet, and a low-carbohydrate diet that did not restrict calories over two years. The low carbohydrate diet resulted in a 4.7 kg weight loss, the Mediterranean diet had a 4.4 kg weight loss, and the low-fat diet had a 2.9 kg weight loss. The low carbohydrate diet also resulted in the most positive effects on the lipid profile with reduced triglycerides and increased high-density lipoproteins (HDLs). The Mediterranean diet was most effective at improving glycemic control in diabetics.

A sub-set of patients may do better on a low carbohydrate diet. Specific characteristics, such as those who spike higher insulin levels after a glucose load, may predict who does better on a low carbohydrate diet (Oh et al., 2021). There is not enough data to accurately predict who will do well on a specific type of diet. The best combination of macronutrients depends on individual factors (Oh et al., 2021 & Kim, 2021).

While low carbohydrate diets and ketogenic diets effectively manage obesity, they are not a panacea. A recent review that looked at multiple types of diets showed significant variation and that weight loss/maintenance plans should be individualized (Kim, 2021).

Overall, low carbohydrate diets are better than low-fat diets at improving HDL and lowering triglycerides but have similar effects on total cholesterol and low-density lipoproteins (Oh et al., 2021). The overall effect on cardiovascular risk is similar between low fat and low carbohydrate diets. Low carbohydrate diets are more frequently associated with side effects such as constipation, headache, muscle cramps, diarrhea, rashes, and weakness (Oh et al., 2021 & Kim, 2021).

The key to lasting weight loss is long-term lifestyle modification. The key to long-term success is changes that last a lifetime, not just ones that result in a ten-pound weight loss in the first couple of weeks (mostly just water). Changing eating and exercise habits by eliminating unhealthy food choices, adding healthy choices, and adding daily or almost daily exercise is the only way to have long-term weight loss. Dietary adherence is a critical factor in weight loss maintenance.

Exercise

Exercise, which increases energy expenditure, helps tip the balance between expended energy over consumed energy. Exercising and burning calories provide tremendous benefits in weight loss and have benefits outside of weight loss.

Fitness improves mortality risk, but being fit and maintaining normal body weight is optimal. Overweight and obese-fit individuals have a 25% and 42% increased mortality risk compared to normal weight-fit individuals. Researchers, healthcare professionals, and public health officials are encouraged to employ exercise interventions to reduce cardiovascular mortality risk (Barry et al., 2018).

Exercise is critical to a successful weight loss or weight maintenance program, in addition to dietary changes. Moderately intense exercise entails thirty minutes of activity five days a week between 150 and 250 minutes per week, leading to modest weight loss. Physical activity greater than 250 minutes a week is associated with significant weight loss. Additionally, weight maintenance is optimized with physical activity greater than 250 minutes a week (Donnelly et al., 2009). Using a pedometer or step calculator can help shed extra pounds. Pedometers and step calculators get individuals to walk more, serve as a motivating factor, and enhance weight loss.

Resistance training should also be included in any weight loss program. Resistance training improves muscular strength and endurance and helps preserve lean muscle mass. Dieting, especially very low-calorie diets, is associated with a loss of muscle mass, and resistance training can ameliorate the loss of lean tissue. In addition, weight-training increases muscle mass.

Muscle mass is more metabolically active and results in higher daily energy expenditure. For example, John weighs 200 pounds. Of that, 140 pounds is lean muscle. His daily energy expenditure is measured at 2,800 calories a day. After two months of weight and endurance training, his weight is now 195 pounds, but his lean mass is 145 pounds. Not only has he lost 10 pounds of fat, but his energy expenditure is now 2,850 calories a day, which may not seem like a lot, but over one year, that is an extra 18,250 calories burnt. If his diet stays the same, he will potentially lose an additional 5 pounds without having to do anything but maintain that muscle mass. Individuals with more muscle burn more energy throughout the day, including watching TV and sleeping.

American culture wants things now, but poor health and obesity have occurred over the years, and reversing this process will not occur overnight. It will take a lifetime commitment. While the reversal of obesity is slow, weight loss will improve mental and physical function.

Table 3: Key points for weight loss
  • To lose weight, eat fewer calories than you expend.
  • Know your BMI and weight goal.
  • Engage in a safe and effective exercise program.
  • Maintain a healthy diet with plenty of fruits and vegetables, complex carbohydrates, low-fat dairy, and lean protein sources.
  • Reduce the quantity of saturated fat in the diet.

Medications

Medications can treat obesity when lifestyle changes alone do not provide the necessary weight loss. Prescription weight-loss drugs are meant for those with a BMI greater than 30 or above 27 with obesity-related conditions, such as HTN, type 2 diabetes, dyslipidemia, or sleep apnea (Singh & Singh, 2020).

Not all medications are effective for all patients. The healthcare professional needs to monitor the effectiveness of the medication. If there is no desirable weight loss of two kilograms over the first month, then therapy should be reconsidered (Perreault, 2022). Changing medications, adjusting the dose, or discontinuing the medications are all options. It is essential to determine if the risk of the medication is worth the benefit of using it. Most side effects of these medications are mild and often improve with continued treatment. Rarely severe and even fatal outcomes have been reported.

Weight loss drugs come with a long history of complications. In the past, thyroid medication was used to increase metabolism, but this led to cases of hyperthyroidism. Many of these cases led to death, as this was done when there were no effective treatments for hyperthyroidism. Amphetamines are used as weight loss aids but have led to addiction in many patients. Most recently, fenfluramine and dexfenfluramine, more popularly known as phen/fen, were associated with valvular heart disease and primary pulmonary hypertension (Dolgin, 2012).

Patients need to have realistic expectations about the efficacy of weight loss medications. Medications are more effective in some patients than others. Multiple medications are approved for weight loss, including:

Pancreatic Lipase Inhibitor Approved for Long-term Use

Orlistat (Xenical®) (Alli®)

Orlistat is available as a prescription and over the counter. Orlistat decreases the body's ability to absorb dietary fat by about one-third (Perreault, 2022). Orlistat alters fat digestion by inhibiting pancreatic lipases, which break down dietary fat. Consequently, the body absorbs less fat and fewer calories. Thus, fat is not completely hydrolyzed, and fecal fat excretion increases.

In normal individuals eating a diet that contains 30% fat orlistat causes a dose-dependent increase in fecal fat excretion, inhibiting the absorption of approximately 25% to 30% of calories ingested as fat (Perreault, 2022).

Orlistat is an excellent first-line option as it is safe and effective. Many benefits beyond weight loss have been shown with Orlistat. One study used 120 mg of Orlistat three times a day along with lifestyle changes. It showed that the risk of type 2 diabetes significantly decreased after four years, and weight loss (10 kg vs. 6 kg) was significantly better than lifestyle changes alone (Perreault, 2022).

In hypertensive patients, Orlistat improves blood pressure (likely due to weight loss), as illustrated by a meta-analysis of four trials comparing Orlistat with placebo in patients with obesity and HTN. There was a significant reduction in systolic and diastolic blood pressure (weighted mean difference -2.5 and -1.9 mmHg, respectively). Patients taking Orlistat also lost significantly more weight (weighted mean difference -3.7 kg) (Perreault, 2022).

Additionally, Orlistat improves some serum lipid values more than can be explained by weight reduction alone. In a multicenter trial, as an example, serum total and low-density lipoprotein (LDL) cholesterol concentrations decreased by 4% to 11% and 5% to 10%, respectively, in patients treated with a weight-maintaining diet plus 30 to 360 mg of Orlistat per day for eight weeks. These decreases were probably related to fecal fat loss. Others have reported a reduction in postprandial hypertriglyceridemia associated with Orlistat therapy (Perreault, 2022).

Potential adverse effects and precautions of Orlistat include cramps, flatulence, fecal incontinence, and oily spotting. Eating a low-fat diet can minimize side effects. Severe liver injury and oxalate-kidney injury have been rarely reported. Orlistat is contraindicated during pregnancy.

Orlistat, available for the long-term treatment of obesity, is provided in 120 mg capsules. The recommended dose is 120 mg three times daily. A lower-dose (60 mg), over-the-counter version is approved and available in some countries, including the US. Two of the 60 mg over-the-counter capsules are the same as one of the 120 mg capsules. Patients should be advised to take a multivitamin at bedtime because Orlistat may decrease the absorption of fat-soluble vitamins (Perreault, 2022).

GLP-1 Receptor Agonists Approved for Long-term Use

The incretin peptides (glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide, also called gastric inhibitory polypeptide [GIP]) are gastrointestinal peptides that stimulate glucose-dependent insulin secretion. GLP-1 also inhibits glucagon release and gastric emptying. GLP-1 receptor agonists bind to the GLP-1 receptor and stimulate glucose-dependent insulin release from the pancreatic islets. GLP-1 receptor agonists were initially approved for the treatment of type 2 diabetes. One of the mechanisms by which GLP-1 receptor agonists improve glycemia in diabetes is due to their ability to induce weight loss (Perreault, 2022)

Two GLP-1 receptor agonists have been approved to treat obesity in the US: Liraglutida and Semaglutide, both administered by subcutaneous injection. For patients with or without diabetes mellitus, these agents are preferred first-line pharmacotherapy to treat obesity. For patients with diabetes, the side effects, need for injections, and expense is balanced by improved glycemia and weight loss.

Treatment with Semaglutide is preferred over Liraglutide because the administration of Semaglutide is once weekly rather than once daily, and Semaglutide has greater efficacy for weight loss than Liraglutide (Perreault, 2022).

Liraglutide (Saxenda®) (Victoza®)

Liraglutide is a chemically modified version of human GLP-1. It is available in the US and Europe in a higher dose (3 mg daily) than used in diabetes for the treatment of obesity in adults with BMI ≥30 kg/m2 or ≥27 kg/m2 with at least one weight-related morbidity (e.g., HTN, type 2 diabetes, dyslipidemia) (Perreault, 2022).

Once-daily, Liraglutide is administered subcutaneously in the abdomen, thigh, or upper arm. The initial dose is 0.6 mg daily for one week. The dose is increased at weekly intervals (1.2, 1.8, 2.4, 3 mg) to the recommended dose of 3 mg. A slower-dose titration is advised if Liraglutide is poorly tolerated (e.g., nausea, vomiting). Additionally, a patient should continue on the maximum tolerated dose (if less than the goal of 3 mg) if the weight loss goal is achieved on that dose (Perreault, 2022).

For patients considered overweight or have obesity, Liraglutide is prescribed at the maximum dose (3 mg daily) to achieve maximum weight loss. Lower doses can be used for patients unable to tolerate this dose as long as ≥4% weight loss is achieved by 16 weeks. In patients who also have type 2 diabetes, glycemic control and weight loss should be monitored (Perreault, 2022).

In diabetes trials, Liraglutide (1.8 or 3 mg daily) was associated with a significant weight reduction (2 to 4 kg) compared with placebo or Glimepiride. Weight loss has also been reported in patients without diabetes who received Liraglutide (Perreault, 2022).

Liraglutide has been shown to reduce major cardiovascular disease events in adults with type 2 diabetes and preexisting cardiovascular disease. The dose of Liraglutide used was lower than the dose recommended for weight loss (1.8 versus 3 mg) (Perreault, 2022). Cardiovascular outcomes with Liraglutide have not been studied in people with obesity who do not have diabetes.

Liraglutide is contraindicated during pregnancy and in patients with a personal history of pancreatitis or a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia 2A or 2B. In addition, for patients taking Liraglutide concurrent with insulin or an insulin secretagogue (e.g., a sulfonylurea), blood glucose should be monitored, and a dose reduction in the insulin or the sulfonylurea may be necessary to avoid hypoglycemia (Perreault, 2022).

Semaglutide (Ozempic®) (Rybelsus®)

Semaglutide is a long-acting GLP-1 receptor agonist that can be administered subcutaneously once weekly to treat obesity. Semaglutide has demonstrated efficacy in weight loss in trials involving patients with and without type 2 diabetes (Perreault, 2022). In the US, both oral and injectable preparations are approved for the treatment of type 2 diabetes, whereas only the injectable form is approved for the treatment of obesity (Perreault, 2022).

The initial dose of Semaglutide is 0.25 mg SQ once weekly in the abdomen, thigh, or upper arm. The dose should be increased at 4-week intervals (0.5,1,1.7, 2.4 mg) until the maximum recommended dose of 2.4 mg weekly is achieved. If an increased dose is not tolerated, the dose escalation should be delayed by 4 weeks. In a 68-week trial, weight loss in the Semaglutide group was 15.3 kg, and only 2.6 kg was lost in the placebo group (Perreault, 2022).

For patients considered overweight or with obesity, it is suggested that Semiglutide injections at the maximum dose (2.4 mg weekly) be administered to achieve maximum weight loss. Lower doses can be used for patients unable to tolerate this dose as long as ≥5% weight loss is achieved. In patients who also have type 2 diabetes, glycemic control and weight loss should be monitored (Perreault, 2022).

Once-weekly subcutaneous Semiglutide has been shown to induce weight loss in individuals considered overweight or with obesity, with or without diabetes. Semaglutide has been shown to reduce major cardiovascular disease events in adults with type 2 diabetes and established cardiovascular disease or chronic kidney disease. However, the dose of Semaglutide was lower than the recommended dose for weight loss (0.5 and 1.0 versus 2.4 mg) (Perreault, 2022).

Adverse effects and precautions of GLP-1 receptor agonists include (Perreault, 2022):

  • Nausea, vomiting, diarrhea, constipation, hypoglycemia in patients with T2DM (more common if used in conjunction with diabetes medications known to cause hypoglycemia), injection site reactions, increased lipase, and increased heart rate.
  • Rarely reported: pancreatitis, gallbladder disease, renal impairment, suicidal thoughts.
  • Causes a modest delay in gastric emptying.
  • Advise patients to avoid dehydration in relation to GI side effects.
  • Monitor blood glucose in diabetic patients and adjust co-administered sulfonylureas (e.g., reduce dose by 50%) and other anti-diabetic medications to prevent potentially severe hypoglycemia.
  • Possible increase in thyroid cancer risk based on murine model data.
  • Contraindicated in pregnancy and patients with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia 2A or 2B.
  • For Semaglutide, monitor patients with diabetic retinopathy for eye complications.

Combination of Phentermine-topiramate Approved for Long-term Use

Phentermine-topiramate (Qsymia®)

In 2012, the US Food and Drug Administration (FDA) approved a preparation of phentermine and extended-release topiramate (in one capsule) for adults with a BMI ≥30 kg/m2 or with a BMI ≥27 kg/m2 with at least one weight-related comorbidity (e.g., HTN, diabetes, dyslipidemia) (Perreault, 2022). Phentermine-topiramate is not recommended for patients with known cardiovascular disease (HTN or coronary heart disease). Phentermine-topiramate may be considered for individuals with obesity who do not have cardiovascular disease, particularly those who do not tolerate Orlistat or Liraglutide. The efficacy and safety of combining generic phentermine with generic topiramate for weight loss (each taken individually) have not yet been established.

Phentermine-topiramate has enhanced weight loss in the first year of use. The initial dose of Phentermine-topiramate is 3.75/23 mg for 14 days, followed by 7.5/46 mg after that. If, after 12 weeks, a 3% loss in baseline body weight is not achieved, the dose can be increased to 11.25/69 mg for 14 days and then to 15/92 mg daily. If an individual does not lose 5% of body weight after 12 weeks on the highest dose, Phentermine-topiramate should be discontinued gradually, as abrupt withdrawal of Topiramate can cause seizures (Perreault, 2022).

Adverse effects and precautions of Phentermine-topiramate include (Perreault, 2022):

  • Dry mouth, taste disturbance, constipation, paraesthesias, depression, anxiety, elevated heart rate, cognitive disturbances, insomnia (higher dose).
  • Abuse potential due to phentermine component.
  • Topiramate is teratogenic (increased risk of oral cleft defects. It is recommended that a negative pregnancy test should be obtained prior to and during treatment and two forms of contraception be used for women of child-bearing potential).
  • Actions of the Topiramate component include inhibition of carbonic anhydrase, rarely metabolic acidosis, and kidney stones that may result from renal bicarbonate loss.
  • Maximum dose with moderate hepatic or renal impairment (CrCl <50 mL/min) 7.5 mg phentermine/46 mg topiramate once daily.
  • Upon discontinuation, tapering of dose over at least 1-week using every-other-day dosing is recommended.
  • Contraindicated during pregnancy, hyperthyroidism, glaucoma, patients taking MAO inhibitors.

Combination of Bupropion-naltrexone approved for long-term use

Bupropion-naltrexone (Contrave®)

Bupropion-naltrexone is not suggested as first-line pharmacologic therapy. It is unclear whether Naltrexone adds anything to the Bupropion effect from the available literature. Owing to the uncertainty about cardiovascular effects, Orlistat or Liraglutide is preferred (Perreault, 2022).

Bupropion-naltrexone could, however, be an option for an individual who smokes, has obesity, and desires pharmacologic therapy for the treatment of both. Additionally, the combination may benefit people with excess caloric consumption from drinking alcohol, given ' 'Naltrexone's stand-alone indication for treating alcohol use disorder. Nevertheless, Bupropion-naltrexone should be avoided in people with severe alcohol dependency who are at risk of alcohol withdrawal and seizures due to the potential for Bupropion to lower the seizure threshold (Perreault, 2022).

The FDA approved the combination of Bupropion-naltrexone in September 2014 as an adjunct to diet and exercise in patients with BMI ≥30 kg/m2, or ≥27 kg/m2 is at least one weight-related comorbidity. Bupropion is a drug used for the treatment of depression and smoking cessation. Naltrexone is an opioid-receptor antagonist used to treat alcohol and opioid dependence (Perreault, 2022).

Compared with placebo, the combination of Bupropion-naltrexone has been shown to reduce weight by approximately 4% to 5%. The initial dose is (Perreault, 2022):

  • Week 1: one tablet (8 mg of Naltrexone and 90 mg of Bupropion) once daily
  • Week 2: one tablet twice daily
  • Week 3: two tablets in the morning and one tablet in the evening
  • Week 4: two tablets twice daily. Maximum daily dose: 4 tablets (32 mg Naltrexone/360 mg Bupropion)

Dose adjustment or avoidance is recommended in patients with renal or hepatic impairment, depending on severity. Adverse effects and precautions Bupropion-naltrexone include (Perreault, 2022):

  • Nausea, constipation, headache, vomiting, dizziness, insomnia, dry mouth.
  • Transient increase in blood pressure (1 to 2 mmHg on average) during the initial 12 weeks of treatment. The heart rate may also be increased.
  • Contraindicated in patients with uncontrolled HTN, seizure disorder, eating disorder, other bupropion-containing products, chronic opioid use, use within 14 days of MAO inhibitors, pregnancy, or breastfeeding.

Noradrenergic sympathomimetic drugs approved for short-term use

Phentermine, Diethylpropion, Benzphetamine Hydrochloride, and Phendimetrazine are the available sympathomimetic drugs approved by the U.S.FDA for the short-term treatment (up to 12 weeks) of obesity because of their potential side effects, the potential for abuse, limited duration of use, and regulatory surveillance. They are contraindicated in patients with coronary heart disease, uncontrolled HTN, hyperthyroidism, or patients with a history of drug abuse. Nevertheless, generic Phentermine (as a single agent) remains the most widely prescribed weight-loss drug, and the observed abuse rate with this drug is low (Perreault, 2022).

The sympathomimetic drugs are rapidly absorbed after oral administration, and peak plasma concentrations are reached within one to two hours (Perreault, 2022). Sympathomimetic drugs reduce food intake by causing early satiety.

Sympathomimetic drugs have a short half-life in plasma. These drugs are metabolized to inactive products in the liver. The major route of elimination is via the kidneys.

The noradrenergic sympathomimetic drugs:

  • Stimulate the release of norepinephrine or inhibit its reuptake into nerve terminals
  • Block norepinephrine and serotonin reuptake
  • May increase blood pressure
Table 4: Dosage of Sympathomimetic Drugs (Perreault, 2022):
DrugDosage
Phentermine (Adipex-P®) (Lomaira®)
  • Immediate-release: 15 to 37.5 mg or divided twice daily
  • Orally disintegrated tablet (ODT): 15-37.5 mg once daily in the morning
  • Immediate-release (Lomaira): 8 mg 3 times daily before meals
Deithylopropion (Tenuate®)
  • Immediate-release: 25 mg 3 times daily, 1 hour before meals
  • Controlled release: 75 mg every morning
Benzphetamine Hydrochloride (Regimex®) (Didrex®)
  • Initial: 25 mg once daily. May titrate up to 25 to 50 mg one to 3 times daily
  • Controlled release: 75 mg every morning
Phendimetrazine (Tartrate®)
  • Immediate-release: 17.5 to 35 mg 2-3 times daily, 1 hour before meals
  • Maximum dose: 70 mg 3 times daily
  • Sustained-release: 105 mg daily in the morning

Phentermine and Diethylpropion are Schedule IV drugs, a regulatory classification suggesting potential for abuse, although the observed rate is very low. Benzphetamine Hydrochloride and Phendimetrazine are Schedule III drugs. These drugs are approved only for short-term administration, widely interpreted as up to 12 weeks. They have been used in combination with other drugs.

Phentermine is the most often prescribed drug for weight loss in the US as a single agent. Because phentermine was approved in 1959 for short-term use for weight loss, there is only one 36-week trial from that period. In this trial, both continuous and intermittent administration of phentermine led to more weight loss than placebo (net weight loss of 7.4 kg) (Perreault, 2022).

Adverse effects and precautions which apply to all noradrenergic sympathomimetic drugs include (Perreault, 2022):

  • Due to their side effects and potential for abuse, sympathomimetics drugs should not be prescribed for weight loss.
  • If prescribed, sympathomimetic drugs should be limited to short-term use (≤12 weeks).
  • Adverse effects include increased heart rate, blood pressure, insomnia, dry mouth, constipation, and nervousness.
  • There is an abuse potential due to amphetamine-like effects.
  • Sympathomimetic drugs may counteract the effect of blood pressure medications.
  • Sympathomimetic drugs should be avoided in patients with heart disease, poorly controlled HTN, pulmonary hypertension, or a history of addiction or drug abuse.
  • Sympathomimetic drugs are contraindicated in patients with a history of CVD, HTN, glaucoma, MAO inhibitor-therapy, agitated states, pregnancy, or breastfeeding.

Surgery

Surgery is reserved for individuals with a BMI of over forty. Surgery is considered if the BMI is 35 or more and the patient is afflicted with an at-risk condition, including sleep apnea, diabetes, heart disease, or a BMI of 30 with difficult to control diabetes or metabolic syndrome (Lim, 2021).

Bariatric procedures come in two different types: restrictive and malabsorptive. The restrictive type includes the vertical banded gastroplasty, sleeve gastrectomy, and the laparoscopic adjustable gastric band. The malabsorptive type includes the jejunoileal bypass, biliopancreatic diversion with duodenal switch, and biliopancreatic diversion. The Roux-en-Y gastric bypass (GYGB) is a combination of restrictive and malabsorptive (Lim, 2021 & American Society for Metabolic and Bariatric Surgery [ASMBS], 2021).

The vertical sleeve gastrectomy limits the amount of food taken into the body and reduces the amount of food used. This procedure uses staples and a band to create a long vertical tube or banana-shaped stomach. The procedure removes most of the stomach and reduces the hormone ghrelin, which lowers appetite. After two years, 60% weight loss is expected (Lim, 2021).

RYGB is the most commonly performed weight loss surgery in the US and is a combined restrictive and malabsorptive procedure. The restrictive part involves creating a small pouch to restrict food intake in the stomach. A section of the small intestine, Y-shaped, is attached to the pouch, so food bypasses the stomach, duodenum, and part of the jejunum to reduce the number of calories absorbed. After two years, weight loss is expected to be 70% (Lim, 2021).

The adjustable gastric band, which is not commonly done, is performed via laparoscope by placing a silicone rubber band around the upper end of the stomach. The banding makes a small pocket and a thin passage to the stomach. An access port is placed so the band can be made more loose or tight with an infusion of saline (ASMBS, 2021).

The biliopancreatic diversion with a duodenal switch is a complex procedure. Due to its high complication rate, it is not commonly performed. It removes a large part of the stomach, similar to vertical sleeve gastrectomy, to restrict the amount of food consumed. In addition, the small intestine is modified, leading to a limited ability of the duodenum to absorb food and vitamins. This procedure also modifies bile and other digestive juices, affecting digestion and the absorption of food. While this procedure may lead to significant weight loss, it can lead to many problems such as anemia, osteopenia, or osteoporosis (ASMBS, 2021).

The single anastomosis duodenal-ileal bypass with sleeve gastrectomy is a newer procedure. It is similar to the biliopancreatic diversion with a duodenal switch but takes less time to perform. The surgery starts with a sleeve gastrectomy, and then the intestine is shortened, and food goes through only the latter part of the small intestine. Digestive juices mix with the food to absorb vitamins and minerals. This surgery can be added to someone who already had a sleeve gastrectomy to enhance weight loss (ASMBS, 2021).

Research shows that weight loss ranged from 13% with adjustable gastric banding one year after surgery to 30.9% with RYGB. Those with gastric sleeves lost 23.4% of their baseline weight (Maciejewski et al., 2016).

Acute complications of these procedures include infection, bleeding, peritonitis, diarrhea, DVT, and PE. Long-term complications often include malabsorption of vitamins and minerals, leading to vitamin deficiencies, abdominal strictures, and hernias (Perreault, 2022).

Vitamins and minerals not absorbed well include vitamin B (vitamin B9 [folic acid] and B12 [cobalamin]), iron, copper, zinc, and calcium. If the surgery diverts the food from the biliary and pancreatic system, the fat-soluble vitamins (A, D, E, and K) are not absorbed well.

Hernias may include incisional hernias or internal hernias. An incisional hernia is a weakness that protrudes from the abdominal wall through a surgical incision. This hernia is less common when a laparoscope is used. An internal hernia occurs when the bowel is trapped in the lining of the abdomen.

Another problem is the dumping syndrome, which occurs after eating a meal high in carbohydrates and food moves too quickly into the small intestine resulting in abdominal pain, nausea, weakness, sweating, bloating, and dizziness (Perreault, 2022).

Weight loss is often accomplished quickly. While benefits may be great, anytime surgery is considered, it must be done carefully as it is associated with risks and complications. Long-term success after surgery is related to the patient's lifetime commitment to behavioral changes. Without continually working on the lifestyle changes, the patient will not get the full benefit from the surgery.

After bariatric surgery, the diet should be modified to prevent complications from the surgery. Careful adherence to the surgeon's recommendations is critical. Referral to a dietitian may also be indicated to assist in eating healthy and safely (especially in the first few months). Some recommendations include:

  • After surgery, a clear liquid diet may be given for 1-2 weeks, followed by a complete liquid diet and then a pureed diet.
  • Eat a low-calorie diet with balanced meals.
  • Consume small portions.
  • Initially, keep calories low (less than 600 calories a day), which will then be gradually increased.
  • Eat slowly.
  • Avoid foods that are not easily chewed: steak, pork, rice, raw vegetables, and fresh fruits.
  • Chew all food thoroughly.
  • Do not use straws and do not drink carbonated beverages as these may introduce air into the GI tract and cause discomfort.
  • Drink water and non-caffeinated low-calorie beverages between meals.
  • Minimize or avoid alcohol altogether as it is absorbed very quickly.
  • Consume high protein foods – try to get at least 65 grams a day.
  • Pills/vitamins that are taken may need to be cut into small pieces to allow them to be absorbed.
  • Supplements are recommended after surgery, including (but not limited to):
    • High potency multivitamin
    • Calcium supplement (1,200 to 2,000 mg a day divided, preferably as calcium citrate)
    • Vitamin D supplement (800 to1,000 international units a day)
    • Vitamin B12 (500 mcg day)

Case Study 2

Kristen K. is a 33-year-old caucasian female who is 5 feet 6 inches tall and weighs 306 pounds. Her BMI is 51.5. She has a waist measurement of 54 inches and a hip measurement of 58 inches for a waist to hip ratio of 0.93. She suffers from HTN, osteoarthritis of her hips and knees, diabetes, and sleep apnea. Her medications include Lisinopril 40 mg a day, Hydrochlorothiazide 50 mg a day, Metformin 1,000 mg twice a day, NPH insulin 40 units in the morning, and 20 units before dinner, Hydrocodone/acetaminophen PRN for pain.

She weighed 280 pounds three years ago and has slowly gained weight despite multiple attempts at lifestyle changes, including exercise and diet, and a trial of medications. She used Orlistat 120 mg three times a day for six months but gained 5 pounds while on this medication. Her compliance was poor with Orlistat due to frequent oily stools and staining of her clothes. She attempted to use Semaglutide but had significant nausea while on this medication. Her physician was reluctant to use Phentermine-topiramate due to her HTN.

Because of her comorbidities, unsuccessful lifestyle changes, and medications, she was referred to a surgeon.

The surgeon decided to perform a Roux-en-Y gastric bypass, and the procedure was performed without any complications. Over the next year, Kristen lost 60 pounds, cut her Insulin dose in half, and reduced her Hydrochlorothiazide to 25mg a day. After the first year, Kristin increased her physical activity significantly and lost another 50 pounds. Her Insulin and Hydrochlorothiazide were discontinued. Additionally, her Lisinopril dose was reduced to 20 mg a day, and she no longer needed any Hydrocodone/acetaminophen for her osteoarthritis.

Conclusion

Obesity is a crucial problem affecting the American healthcare system, and it is associated with many common, chronic diseases and reduces the quality of life. Nurses have a vital role in helping the healthcare system identify obese patients, educate them, and implement interventions to reduce obesity.

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