In almost every clinical day, it is a common occurrence for at least two to three patients to ask for counsel on weight loss strategies, diet choices, and how to manage their weight, even when the reason for their visit is totally unrelated to weight management or obesity. For the busy NP, information on nutrition, diets, and obesity treatments can be overwhelming. Which diet for which type of patient? Which medication will work for which patient? Where and when do we begin?
This article explores the recent American Association of Clinical Endocrinologists (AACE) and American College of Endocrinology (ACE) guidelines on obesity management and weight loss recidivism in adult populations, analyzes common fad diets and their medical contraindications, and reviews pharmacologic interventions available to treat obesity.
Healthcare providers realize that obesity is a growing epidemic on a global level, with more than 600 million adults with a body mass index (BMI) of greater than 30 and more than 42 million children qualifying as overweight or obese.1 In the United States, the average person consumes excess amounts of fat, glucose, and sodium annually. Warren and colleagues reported that the average consumption per person each year includes 29 lb of French fries, 23 lb of pizza, 24 lb of ice cream, 53 gallons of soda, 24 lb of artificial sweeteners, 2.7 lb of salt, and 90,000 mg of caffeine.2
Overweight and obese individuals often look for a quick fix to their weight problems. The CDC has an entire section of their website (www.cdc.gov/obesity) dedicated to obesity; their statistics indicate an alarming upward trend in the incidence of obesity per capita over the last 40 years. The effects of obesity increase the potential onset of multiple chronic diseases, including type 2 diabetes mellitus (T2DM), hypertension, certain cancers (colorectal, esophageal, lung, kidney, and postmenopausal breast cancer), coronary heart disease, end-stage kidney disease, gallbladder disease, and depression as well as other common mental disorders.3,4
AACE and ACE developed a comprehensive guideline for medical care of patients with obesity, which was published after an intensive review of the evidence available on obesity, obesity management, and obesity consequences.5 The end result was a recommendation that obesity is a highly complex, adiposity-related chronic disease that requires multiple levels of medical management, including screening, diagnosis, evaluation, treatment goals, and follow-up supervision to facilitate high-quality care of patients with obesity.
The guidelines provide more than 123 recommendations, covering health screenings, lifestyle modifications, and therapeutic management options. One of the initial recommendations from the AACE/ACE recommendations was that the diagnosis of obesity should not be based solely on the anthropometric component (BMI) but should also consider the presence and severity of obesity with a high BMI and related complications.5
In patients with an elevated BMI and comorbid conditions such as diabetes, dyslipidemia, nonalcoholic fatty liver disease, hypertension, sleep apnea, and osteoarthritis (particularly in weight-bearing joints), weight loss can help reduce the BMI and can also help patients gain better control and management of the comorbid condition.5 As this article analyzes key components of obesity management, the AACE/ACE guidelines will be used as a benchmark for comparison and discussion in adult patients with obesity.
An initiative on the CDC website (www.choosemyplate.gov) provides excellent patient information and guidance for healthy living and weight control. The CDC's healthy plate examples teach portion control and healthy food choices and also recommend finding a balance between food and physical activity. This website is user-friendly and easy to read and understand, making it a great resource for all ages.
Also on the CDC website is a link to the Dietary Guidelines for Americans 2015-2020, Eighth Edition, which provides essential information on healthy diet choices, exercise, and lifestyle modifications to promote positive health.6 The five key components of the Dietary Guidelines are choosing healthy eating patterns across the lifespan, consuming a variety of foods from the food groups, limiting high-fat and high-sugar choices, making healthier beverage choices, and supporting healthy eating patterns for all.6
The AACE/ACE guidelines recommend lifestyle therapy for patients who are overweight or obese. The lifestyle recommendations include a low-calorie meal plan, increased physical activity, and behavioral interventions. The behavior intervention package can include self-monitoring of weight, food intake, and physical activity; clear and attainable goal setting; group meetings; stimulus control; educational interventions on diet, nutrition, and exercise; cognitive behavioral therapy; and psychological counseling if indicated.5
It is common for a multidisciplinary team comprised of primary care providers, nurses, dietitians, exercise coaches/trainers, and clinical psychologists to be included in the management of overweight and obesity. Diagnostic studies are recommended prior to treating obesity to identify any underlying medical problems. Diagnostics should include lab studies to evaluate blood glucose (fasting glucose, A1C), a lipid panel, and liver function studies. Other screening tests should be considered based on individual risk factors and patient presentation.5
The Dietary Guidelines for Americans 2015-2020, Eighth Edition recommends regular physical activity along with a healthy eating pattern to improve adult health. Based on the recommendations, adults need at least 150 minutes of moderate-intensity physical activity and muscle strengthening exercise on 2 or more days per week.
The AACE/ACE guidelines recommend both aerobic training and resistance training for overweight and obese individuals. Their recommendations encourage aerobic exercise on a progressive course, beginning initially at a pace that is tolerable and working toward an endpoint goal of over 150 minutes weekly spread over three to five sessions per week. Overweight and obese patients should be encouraged to engage in resistance training with a fitness professional, which can help reduce adipose tissue while preserving lean muscles in the major muscle groups.
The recommendations are to include resistance workouts two to three times weekly.5 Provider recommendations for physical activity should be individualized to consider the capabilities of the patient as well as any physical limitations. Patients with serious comorbid health conditions (particularly cardiac and respiratory diseases) should be evaluated medically to make certain that they are capable of participating in an exercise program.
When an obese person expends energy through exercise, the body produces a metabolic adaptation in effort to conserve energy, and therefore, weight loss does not occur. Once the individual reaches the weight loss goal, he or she needs to continue to lower caloric intake in order to maintain the lower body weight (otherwise, the patient will regain the lost weight more easily).1 In this altered metabolic state, the individual must consume 15% fewer calories to maintain weight loss.
There are higher levels of leptin in the fat mass that become resistant to the anorexigenic properties of leptin, glucose, and insulin. Additionally, the skeletal muscles save fuel in the form of adipose cells. Many individuals can experience weight loss, generally for a few months, but few can sustain the weight loss over a longer period of time.7,8
The weight loss diet industry has made billions of dollars in the United States by selling information and diet products promoting weight loss to overweight and obese individuals. Commercials and advertisements on TV, magazines, billboards, social media, and other places offer promises that often seem too good to be true. With this preponderance of diet and weight loss advertising and claims, how does the average adult determine which weight loss method will be safe and effective? Hopefully, these questions are being raised in the visits in the health clinics or in nutrition centers.
There are thousands of diet plans on the market. A visit to the local bookstore reveals an entire section dedicated to weight loss, all with the same promises: guaranteed weight loss. For the sake of this article, the most popular current diets have been organized into categories: low-calorie diets, low-carbohydrate diets, meal replacement diets, and life pattern diets. Each of these will be discussed in relationship to their effectiveness and their medical contraindications or warnings.
The AACE/ACE guidelines recommend a reduced-calorie, healthy meal plan, which essentially cuts 500 to 750 calories per day from the normal dietary intake. This can be accomplished in any number of diet plans, including the Dietary Approaches to Stop Hypertension (DASH) diet, Mediterranean diet, low carbohydrate, low fat, high protein, vegetarian diets, and even through meal replacements. Very low-calorie diets should only be an option if the individual is going to be closely supervised by a healthcare professional on a frequent schedule.5
Low-calorie diets. Two popular low-calorie diets on the market include Weight Watchers and Jenny Craig diets, both of which recommend balanced diets with 1,200 to 1,500 calories and provide individualized counseling and follow-up. Both Jenny Craig's and Weight Watchers' websites provide small, anecdotal research studies showing positive outcomes for their patrons. Both of these programs offer nutrition counselors and support programs to assist the dieter through the weight loss process. Weight Watchers offers small weekly group meetings, providing education and support for members.9
One of the major physiologic problems with low-calorie diets is that as weight loss occurs, the body's energy requirements also go down; therefore, unless the individual maintains low-calorie consumption, they will experience recidivism.1 Complications that may occur with sustained low-calorie consumption may include ketosis (especially if also on low carbohydrate consumption), excessive loss of lean body mass, cardiac dysrhythmias, and dehydration. Patients on a very low-calorie consumption diet (800 calories/day) may see improvements in total cholesterol triglycerides and glycemic control but may also experience cholelithiasis, sudden death, cold intolerance, hair loss, muscle cramping, dizziness, and headaches.10
The DASH diet is a healthy low-calorie diet plan that focuses on higher concentrations of fruits and vegetables (11 servings per day), grains (6 servings per day for a 1,600 calorie diet and 7 to 8 servings per day for a 2,000 calorie diet), low-fat dairy (2 servings), and reduced amounts of meat, poultry, fish, sweets, desserts, oils, and fats. A meta-analysis of the DASH diet demonstrated significant improvement in dietary intakes, significant drops in total fat and cholesterol intakes, and positive changes in BP recordings.11
Low-carbohydrate diets. Included in the common low-carbohydrate diet plans are the Atkins plan, The Zone, Sugar Busters, and South Beach diet plans. Patients on these diets may see positive weight loss while on the plan, but once they return to their normal patterns of eating, the weight frequently returns. These plans effectively work by depleting glycogen stores, which produces diuresis and subsequent weight loss.12 The adverse reactions of low-carbohydrate diets include ketosis, nausea, fatigue, constipation, and elevated uric acid levels.
Glomerular damage can occur and accelerate kidney disease with low-carbohydrate diets due to excessive spilling of proteins, which can cause tubular injury. In addition, urinary calcium increases, thus increasing the risk of renal calcium stone formation.13 Prolonged ketosis can result in hyperlipidemia, impaired neutrophil function, optic neuropathy, osteoporosis, protein deficiency, and alterations in cognitive function. Additionally, low-carbohydrate diets limit consumption of fruits, vegetables, and grains, leading to potential deficiencies of vitamin B, calcium, potassium, and phytochemicals.
Meal replacement diets. There are many meal replacement diets available on the market. Three of the more commonly used meal replacement diets will be discussed: SlimFast, Medifast, and Nutrisystem. Each of these diet programs provide some research evidence to support their claims to weight loss management. Essentially, each program provides their product as a meal replacement to provide low-calorie portion-controlled meals, which are often available as full meals, shakes, protein bars, and frozen foods. Nutrisystem's weight loss plans provide reduced sodium intake (50% less than typical American diets) and 70% less sugar, with no monosodium glutamate, artificial sweeteners, or stimulants. Nutrisystem's website advertises a price range from $305 to $418 per month, depending on the type of products purchased (www.nutrisystem.com). Medifast's website advertises their program for $10.97 per day (www.medifast1.com).
Medifast presents research evidence supporting their program's ability to lower low-density lipoprotein (LDL) cholesterol levels and minimize loss of lean body mass by providing 70 g to 90 g of protein daily, with meals that are fortified with 24 vitamins and minerals. Patrons on this diet consume 5 Medifast products each day along with one “lean and green meal.” Research demonstrated robust weight-related and health-related results, fast initial weight loss, and improvement in health parameters.14,15 Patrons can purchase their Medifast products through a company counselor who is available to provide weekly telephone and personal coaching sessions.
SlimFast is marketed as a meal replacement program with a wide array of snacks, protein bars, shakes, and other food products. In a systematic review of commercial weight loss programs, Gudzune and colleagues noted mixed results in four randomized controlled studies using SlimFast, noting that attrition and adherence were variable.16,17 The company provides easy-to-follow, easy-to-attain, low-calorie, portion-controlled weight loss products.
Life pattern diets. Some of the more commonly used diet plans over the past 10 years have included the China Study, the Mediterranean diet, variations of vegetarian diets, low-gluten diets, and the Daniel plan. Vegetarian diets provide rich dietary fiber, reduced calories, and increased satiety. The satiety factor is attributed to the increased mastication required for consuming healthy portions of high-fiber vegetables. One of the major problems with vegetarian diets is limitations in full fat, dairy foods, and refined carbohydrates. Individuals on these diet plans may experience deficiencies in omega 3, vitamin D, vitamin B12, calcium, zinc, and iodine.10
The China Study presents an interesting review of diet options; with a typical diet that is higher in calories than the typical American diet, it is significantly lower in total protein, animal protein, and total fat. The diet plan emphasizes unlimited fruits, vegetables, and whole grains while limiting refined carbohydrates, vegetable oils, salmon, tuna, and cod. Individuals following this diet plan avoid red meat, chicken, dairy products, eggs, and egg products.18 As with the vegetarian diet, this diet plan can produce deficiencies in vitamin B12 and vitamin D. Research reported in the study demonstrates that adherence to the China Study diet can lead to improvements in overall health and decreased episodes of certain cancers and cardiovascular illnesses as compared with the typical American diet consumption.18
The Mediterranean diet recommends micronutrient-dense (vitamins and minerals) and low-glycemic plant-based foods that are high in fiber and produce increased satiety and satisfaction. The diet includes animal and plant proteins (1 g to 2 g pure protein per 2.2 lb of body weight daily) and low-glycemic carbohydrates. Additionally, consumption of wine in limited quantities is permitted.19,20 Research studies have demonstrated modest improvements in BP, improvement in LDL and triglycerides, reduction in cardiovascular risk factors, and a decrease in mortality risk.21,22
The Daniel plan is based on the biblical story of Daniel, a young Jewish man in 605 B.C.E. who challenged his Babylonian captors to allow him to continue his normal cultural diet of lean proteins, whole grains, and nonstarchy vegetables rather than consuming from the king's table of high-calorie foods.2
The components of the Daniel plan include consuming a healthy diet and maintaining a healthy spiritual life. The diet plan encourages patrons to consume 5 to 9 servings daily from the “rainbow” of colors (naturally occurring orange, red, yellow, green, purple, and blue foods), which covers all the essential phytonutrients needed on a daily basis. This diet minimizes sugars and white flours and focuses on fiber, protein, portion sizes, healthy foods, exercise, and adequate sleep.2
Gluten-free diets were traditionally recommended for patients with celiac disease to prevent immunologic reactions to gluten in the lining of the small intestine. Recent research has demonstrated a link between gluten sensitivity and low vitamin D, osteoporosis, and nonsteroidal anti-inflammatory drug (NSAID) use.23 Following a gluten-free diet can precipitate deficiencies in vitamin B12, vitamin K, vitamin D, zinc, iron, folate, calcium, magnesium, and dietary fiber.24-28
Intermittent fasting plans are a newer weight-loss trend in the United States. These diets claim improvement in metabolic functioning, which leads to healthier overall outcomes for blood glucose, BP, and energy. Several plans are available, with the most popular ones including a 16/8 plan, emphasizing that followers should fast for 16 consecutive hours each day and only eat during the remaining 8 hours each day (for example, fast from 7:00 p.m. until 11:00 a.m. on the next day and eat only from 11:00 a.m. until 7:00 p.m.); a 5:2 plan which includes 2 days each week of fasting (consuming fewer than 500 calories per fasting day); and alternate-day fasting, in which the individual fasts (consumes less than 500 calories per fast day) every other day.
Feeding days are unlimited in food choices, but recommendations are to include healthier, low-fat, low-calorie foods on feeding days.29-31 Endocrinologists often recommend intermittent fasting plans for patients who have T2DM to help combat insulin resistance; however, this diet approach requires strict monitoring and medication adjustments for the patients following a 72-hour fast period (see Summary of diet plan effects and cautions).32
The National Heart, Lung, and Blood Institute (NHLBI) recommends initiation of pharmacologic approaches to manage weight loss for individuals with a BMI of 30 or greater or in those who have a BMI of 27 or greater with concomitant risk factors (www.nhlbi.nih.gov/files/docs/guidelines/prctgd_c.pdf). Patients on these medications require regular follow-up visits every 2 to 4 weeks to monitor BP, weight, heart rate, and lab values. If a patient fails to lose 4.4 lb (2 kg) in the first 4 weeks, the NHLBI recommends discontinuation of the drug. The recommendations from the AACE/ACE indicate that the addition of pharmacotherapy produces more robust weight loss and weight-loss maintenance than lifestyle modification therapy alone; however, pharmacotherapy should not be used without the addition of lifestyle therapies.5 Key considerations in selecting a pharmacotherapy agent for weight loss include careful review of the potential adverse reactions, cautions, and warnings for each medication.
Orlistat is a lipase inhibitor that reduces fat absorption by approximately 30% and inhibits digestion of dietary triglycerides and lipid-soluble vitamins (A and E). The AACE/ACE guidelines note that orlistat may be an acceptable agent for use in obesity management for patients diagnosed with end-stage renal failure but must be used with caution due to the risk of calcium oxalate stone formation. It is not recommended for use during pregnancy or lactation.5 The drug is contraindicated in chronic malabsorption syndrome and cholestasis.33
Phentermine-topiramate ER (Qsymia) is an appetite suppressant that produces an energy boost. The AACE/ACE guidelines note that phentermine-topiramate ER should not be used in patients with severe kidney impairment.5 Phentermine-topiramate ER can increase the heart rate, so it is important to monitor heart rate regularly and use the drug with caution in patients with cardiac or cerebrovascular disease. This drug is contraindicated during pregnancy and in patients with glaucoma or hyperthyroidism, and in those currently taking or within 14 days of monoamine oxidase inhibitor use.5 Patients taking the drug should also be monitored for suicidal behaviors and ideations.34
Lorcaserin HCl (Belviq) promotes satiety in patients, with a 7% weight loss predicted within 1 year. Patients on lorcaserin HCl have demonstrated improvements in blood glucose, BP, and cholesterol levels. The drug is contraindicated in children under 18 years of age, during pregnancy, and in patients taking serotonin or antidopaminergic drugs. The drug may cause a severe drop in blood glucose in patients with diabetes. Use the drug with caution and monitor the heart rate in patients with bradycardia and second or third atrioventricular heart block. The drug may decrease red blood cell counts, and NPs will need to monitor the complete blood cell count regularly.5,29,35
Naltrexone SR-bupropion SR (Contrave) is a combined agent that is effective in achieving weight loss, as it decreases food cravings and appetite. This drug is contraindicated in patients with uncontrolled hypertension; seizures; anorexia nervosa or bulimia nervosa; chronic opioid use; concurrent monoamine oxidase inhibitor use; concurrent discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs; and pregnancy.5 It is the preferred agent with a history of or risk of nephrolithiasis and can be used with caution in patients with cardiac or cerebrovascular disease as long as the heart rate and BP are carefully monitored.5,29,36
Liraglutide (Saxenda) is a glucagon-like peptide 1 receptor agonist that is useful in reduction of caloric intake and appetite reduction. The drug is an acceptable choice for patients with nephrolithiasis and in hypertension and cardiovascular diseases, but the heart rate needs to be monitored regularly. The drug should be used cautiously in patients with T2DM who are taking sulfonylureas as it may precipitate a decrease in the blood glucose level. NPs should monitor patients with hepatic disease for signs of cholelithiasis and avoid use of liraglutide in patients with a history of pancreatitis or medullary thyroid disease.5,29,37-39 The drug is contraindicated in patients with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2, and in pregnancy.37
Establishing healthy, realistic weight loss goals
The primary goal of obesity management should be to improve the patient's health by prevention and treatment of weight-related complications of obesity. Weight loss is a definite part of the management, but not the end outcome desired in the AACE/ACE guidelines.5 To that end, NPs should establish some screening standards to evaluate patients who are at risk for adiposity-related disease. This should include BMI levels and waist circumference for any patient over 35 BMI. Those at risk for overweight or obesity should be screened for prediabetes and T2DM as well as metabolic syndrome by assessing the waist circumference, fasting glucose levels, A1C, BP, and lipid profile.5
Obesity is a chronic medical condition that requires a comprehensive approach to attain successful outcomes. NPs should recognize that many chronic diseases they are treating in their patient population, including diabetes mellitus, hypertension, hyperlipidemia, orthopedic joint complaints, among many others, can often be treated in part through weight loss. Effective obesity management in the primary care office requires a multidisciplinary approach.
Team members should include nutrition counselors, exercise trainers, behavioral management, and support persons to help the patient achieve success. All weight lost and kept off lays the foundation for a longer and more productive quality of life.