Diet, Physical Activity and Behavioral Approaches

Dietary Interventions

In order to achieve weight loss, an energy deficit is required. There are multiple approaches in counseling a patient regarding achievement of this goal. The provider may create a specific caloric target, which typically ranges from 1,200-1,500 kcal/day for women and 1,500-1,800 kcal/day for men. The caloric goal may need to be adjusted for their baseline body weight and physical activity level. Another approach is to estimate the individual’s specific requirements and reduce it by 500 kcal/day or approximately 30% energy deficit. Finally, an ad libitum approach is where a formal energy deficit target is not defined, however, lower caloric intake is achieved by restricting or eliminating one or more particular food groups (for example, carbohydrates).

Dietary intervention alone shows average weight loss is maximal at 6 months with small losses maintained for up to 2 years. Weight loss with dietary interventions ranges from 4 kg to 12 kg at 6 months, then slow weight regain is observed with total weight loss at 1 year of 4 kg to 10 kg and at 2 years, 3 kg to 4 kg.

Very Low Calorie Diets (VLCDs)

VLCDs are defined as diets providing <800 kcal/day. VLCDs are designed to provide rapid weight loss while maintaining lean body mass. They can be effective at improving some of the parameters of diseases that are associated with obesity, including uncontrolled diabetes, obstructive sleep apnea (OSA) and hypertension. They often consist of four to five high protein shakes per day in addition to vitamin and mineral supplements. The protein content is typically high and fat content relatively low. Typically, VLCDs are prescribed for no more than 16 weeks and are followed by a re-feeding diet before returning to regular food.

VLCDs are safe and effective when used in appropriately selected individuals with obesity (BMI >30) and require close physician supervision. Patients need a thorough workup to ensure that they can endure such rapid weight change. Side effects may include fatigue, dizziness, hair loss and increased risk of gallstones. VLCDs may induce weight loss of 20% to 25% of initial body weight during the first 12 to 16 weeks of treatment; however, they are not well maintained. Patients typically regain 35% to 50% of the weight loss within the first year following treatment and regain all of the weight by years 3 to 5. Thus, while VLCDs provide very good short-term weight loss and may be appealing for patients, one needs to consider the long-term success.

Protein-Sparing Modified Fast (PSMF)

Total fasting reduces or eliminates hunger and effectively induces rapid weight loss. However, its application is limited due to the significant protein catabolism coupled with undesirable physiologic effects. The Protein-Sparing Modified Fast (PSMF) was developed by Bistrian, Blackburn, and colleagues. A total fast is modified with the addition of 1.5 g/kg of ideal body weight of animal protein from egg albumin, lean meat, or fish. By adding protein, the fasting-associated nitrogen loss declines and allows for preservation of normal liver, endocrine and hematopoietic functions. Carbohydrates are prohibited on this diet and fat is restricted to the protein source. Patients also receive a daily multivitamin in addition to supplemented sodium chloride, potassium and calcium. The PSMF is characterized by a fall in serum insulin and glucose concentrations, a rise in free fatty acid and ketone levels and the appearance of ketonuria, similar to what happens in a total fast. Ketone bodies are important for protein sparing in total and semi-starvation, substituting for protein-derived glucose as a fuel for the brain. Weight loss ranges from 1 to 3 kg weekly, depending on the patient’s age, height, weight, sex and level of activity. The PSMF should be restricted to patients who are at least 30% above their desirable weight with substantial increased risk of morbidity and mortality associated attributed to their obesity.

Low Calorie Diets (LCDs)

Low calorie diets typically provide 1,200 to 1,500 kcal/day and are intended to produce a more modest weight loss, typically producing an average of 0.5 kg/week of weight loss. Most weight loss diets (Table 8-1) are considered low calorie diets. When comparing VLCDs vs LCDs, data have shown that VLCDs result in greater short-term weight loss (16.1% vs 9.7%) but similar weight losses after 1 year (6.3% vs 5%).

Enlarge 

Low Carbohydrate Diets

Low carbohydrate diets restrict carbohydrate intake to 50-100 g daily without limitations on fat and caloric intake. The consumption of high protein foods has been shown to promote satiety. Further, by limiting an entire food group, total daily caloric intake levels fall.

Low Energy Density Diets

Energy density is defined as the number of calories in a given weight of food. The principle behind low energy density diets is that for the same amount of calories a larger volume of food can be consumed when the food is low in energy density vs high density. Thus patients may be more satisfied for a lower number of calories. In a study by Ello-Martin and associates, women with obesity were randomized to a diet focusing on reducing fat intake or one that emphasized both fat reduction and increased intake of water-rich foods (fruits and vegetables). Subjects assigned to increase their water-rich foods lost significantly more weight (8.9 kg vs 6.7 kg); but, at 12 months, weight-loss maintenance was not significantly different. However, those in the water-rich food group reported significantly less hunger.

Low Glycemic Index Diets

The Glycemic Index (GI) is a system that ranks carbohydrate-containing food according to its effect on blood sugar levels, with pure glucose ranking highest (100) on the GI scale. A food’s GI is determined by measuring rises in blood glucose after consuming 50g of available carbohydrate of a particular food compared to the same amount of carbohydrate from a reference food (typically glucose). Based on their GI, foods items may be divided into high-GI (GI≥70), medium-GI (55 ≤ GI < 70) and low-GI (GI < 55) foods. Carbohydrates that are easily digested, quickly absorbed into the blood stream and cause a quick rise in glucose are termed high GI foods. The quick increase in blood sugar level after ingestion of high GI foods also leads to a sharp rise in insulin levels. Low GI foods contain carbohydrates that are digested less rapidly, which causes a slower, more sustained release of sugar into the blood stream and leads to a slower insulin response.

Low GI diets have been shown to reduce glycated hemoglobin, fasting glucose, (body mass index) BMI, total cholesterol, and (low-density lipoprotein (LDL) in patients with type 1 diabetes (T1D), type 2 diabetes (T2D), or impaired glucose tolerance and are therefore recommended for glycemic control and weight reduction in this population. Flattening the postprandial glucose levels may lead to longer satiety and less hunger, which may aid in weight reduction. In a large systematic review of 101 randomized controlled trials comparing low glycemic diet with other diets in patients with overweight or obesity, it was demonstrated that low GI diets yield similar weight reduction results as other diets. However, in studies where the patients achieved a GI reduction of 20 points or more in their diet, weight reduction significantly exceeded other diets. This demonstrates the effectiveness of low glycemic diet on weight reduction and highlights the importance of diet adherence.

Mediterranean Diet

The Mediterranean diet is considered to be the healthiest dietary pattern available to reduce the prevalence of overweight and obesity and it has been ranked #1 in the Best Diet score in regards to body weight and adiposity. Although no strict definition of what is considered the Mediterranean diet exists, its characteristics include: high fat intake that comes predominantly from extra-virgin olive oil (a monounsaturated fat), high intake of low glycemic index carbohydrates, moderate intake of fish, small to moderate consumption of dairy and poultry and low consumption of red meat. The large scale PREDIMED study investigated the impact of the Mediterranean diet on the incidence of cardiovascular disease (CVD) in older patients who did not have CVD at baseline. After 4.8 years, the study revealed hazard ratios of 0.69 (95% CI, 0.53–0.91) for a Mediterranean diet with extra-virgin olive oil and 0.72 (95% CI, 0.54–0.95) for a Mediterranean diet with nuts, compared to the control reduced-fat diet.

In the same study, long term effects of ad libitum consumption of a Mediterranean diet on body weight and waist circumference were analyzed. Compared to the control group, a reduction in body weight of –0.43 kg (95% CI –0.86 to –0.01; P=0.044) with the Mediterranean diet with extra-virgin olive oil and of –0.08 kg (–0.50 to 0.35; P=0.730) for the Mediterranean diet with nuts was observed. The reduction in waist circumference was –0.55 cm (–1.16 to –0.06; P=0.048) in the Mediterranean diet with olive oil group and –0.94 cm (–1.60 to –0.27; P=0.006) in the nut group, compared with the control group. These results demonstrate that even without combining the Mediterranean diet with energy restriction, the participants did not gain body weight and demonstrated a reduction in central adiposity.

Intermittent Fasting

Intermittent fasting (IF) is a term for dietary regimens where periods of restricted energy intake (fasting) are alternated with periods of normal feeding. These dietary patterns are also often referred to as intermittent energy restriction (IER). There is a substantial degree of variation in the IF regimens, from fasting periods lasting for multiple days, to so-called time-restricted feeding (TRF), where the eating time window is restricted to 8 hours a day for several days of the week.

A recent systematic review and meta-analysis tested the effect of various types of intermittent fasting regimens on obesity-related health outcomes. The study identified 28/104 (27%) associations of IF with beneficial metabolic and anthropometric outcomes that were statistically significant. Of the IF regimens, modified alternate-day fasting and fasting once or twice per week were associated with statistically significant weight loss of more than 5% in adults with overweight or obesity. Overall, the study results suggest that IF strategies can be effective in improving obesity-related health outcomes and promote weight reduction.

Meal Replacements

The use of meal replacements (defined as functional foods in the form of a drink or a bar) as part of an overall treatment strategy has been shown to be beneficial and to an extent proportional to the number of meal replacements used over a period of several years. A partial meal replacement (PMR) plan typically prescribes a low calorie (>800 or ≤1,600 kcal/day) diet whereby one or two meals are replaced by commercially available, energy-reduced product(s) that are vitamin and mineral fortified and includes at least one meal of regular foods. By reducing the variety of foods in the diet and increasing dietary structure, meal replacements facilitate adherence to the daily calorie goal. Meal replacements may also help patients who find themselves in challenging situations where they would otherwise make an unhealthy food choice (e.g., when in car running late to work, they may use meal replacement vs stopping at fast food restaurant). Furthermore, meal replacements are often very convenient and eliminate the need to make decisions about how and what type of food to eat.

A meta-analysis revealed that subjects prescribed either both partial meal replacement (PMR) or a standard calorie deficit treatment plans lost significant amounts of weight at both the 3-month and 1-year evaluation time points, however there was greater weight loss in subjects receiving the PMR plan. The PMR group lost approximately 7% to 8% body weight and the randomized, controlled design (RCD) group lost approximately 3% to 7% body weight.

Evaluation of factors associated with 1-year weight-loss success from the Look AHEAD study demonstrated that the number of meal replacements consumed in the first 6 months was significantly related to weight loss at week 26. Further, participants in the highest quartile of meal replacement use had four times greater odds of reaching the 7% weight-loss goal and 4.1 times greater odds of reaching the 10% weight-loss goal than participants in the lowest quartile.

Comparison of Macronutrient Content

There are multiple diet approaches available, each with specific regulations around nutrient content. In four meta-analyses of diet comparison, each summarizing 13 to 24 trials, the only consistent finding was that adherence—the degree to which participants continued in the program or met program goals for diet and physical activity—was most strongly associated with weight loss and improvement in disease-related outcomes. Macronutrient content may influence dietary adherence via the satiating properties of protein, carbohydrates and fat. However, dietary content is only one of many factors influencing adherence. The assumption that one diet is optimal for all persons fails to acknowledge the variation in adherence influenced by food preferences, cultural or regional traditions, food availability and food intolerances.

Sacks and colleagues compared weight-loss diets with different compositions of fat, protein and carbohydrates. The study randomly assigned 811 adults with overweight or obesity to one of four diets; the targeted percentages of energy derived from fat, protein and carbohydrates in the four diets were 20, 15 and 65%; 20, 25 and 55%; 40, 15 and 45%; and 40, 25 and 35%. The diets consisted of similar foods and patients were followed for 2 years. The primary outcome was the change in body weight between the low fat vs high fat and average protein vs high protein and in the comparison of highest and lowest carbohydrate content. At 6 months, participants assigned to each diet had lost an average of 6 kg, which represented 7% of their initial weight; they began to regain weight after 12 months.

By 2 years, weight loss remained similar in those who were assigned to a diet with 15% protein and those assigned to a diet with 25% protein (3.0 and 3.6 kg, respectively); in those assigned to a diet with 20% fat and those assigned to a diet with 40% fat (3.3 kg for both groups); and in those assigned to a diet with 65% carbohydrates and those assigned to a diet with 35% carbohydrates (2.9 and 3.4 kg, respectively) Among the 80% of participants who completed the trial, the average weight loss was 4 kg. Ultimately, all of the reduced-calorie diets resulted in clinically meaningful weight loss, regardless of which macronutrients they emphasized.

Ultimately, the specific diet itself does not determine the success with weight loss, but rather the ability of the patient to adhere to the defined diet is of utmost importance. Furthermore, all approaches can lead to meaningful weight loss if a reduction in dietary energy is achieved.

Limiting Consumption of Ultra-Processed Foods

Ultra-processed foods have been defined as “formulations mostly of cheap industrial sources of dietary energy and nutrients plus additives, using a series of processes” that are being widely consumed due to high availability and low cost. A recent randomized controlled trial investigated the effect of consumption of ultra-processed food on energy intake. Subjects were admitted for 28 days and were randomized into two groups of 10 people, with each group receiving either ultra-processed or unprocessed diet for two weeks, followed by two weeks on the alternate diet. Ultra-processed and unprocessed meals were matched for total calories and other nutritional parameters, but the participants were allowed to consume the meals in ad libitum quantities within a 60-minute window, 3 times a day. During the ultra-processed diet consumption phase, the consumption of calories increased by 508 ± 106 kcal/day (P=0.0001) and there was a strong correlation between the energy intake and weight change (r = 0.8; P <0.0001).

This suggests that a diet consisting of overconsumption of ultra-processed foods leads to excessive energy intake which may lead to weight gain. Another large multinational prospective cohort study of 348,748 participants has also found a positive association between weight gain and high consumption of ultra-processed diet. It also found that higher intake of ultra-processed food was associated with 15% greater risk (95% CI 1.11–1.19) of developing overweight in subjects with regular weight at baseline and 16% greater risk (95% CI 1.09–1.23) of developing obesity in participants with overweight at baseline.

Considering Food Order

In addition to diet composition, the order of intake of nutrient groups has an effect on postprandial sugar and hormone levels. In a pilot study of 11 subjects with T2D, it was found that the blood glucose levels after a meal decreased by 28.6% (P=0.001), 36.7% (P=0.001) and 16.8% (P=0.03) at 30, 60 and 120 min, respectively, in subjects who consumed carbohydrates after vegetables and proteins compared to subjects who consumed carbohydrates first. A reduction in postprandial insulin levels at 60 min and 120 min after the meal were observed in the group that consumed carbohydrates last. Another study investigated the effect of consumption order of carbohydrates on the appetite-stimulating hormone ghrelin. In this study, 16 subjects with overweight or obesity and T2D consumed carbohydrate-first meals, carbohydrate-last meals and sandwich meals where the food groups were ingested all at once. The study demonstrated changes in ghrelin levels from baseline of -11.45% ± 3.86% and 4.13 ± 4.38% (P = 0.003) in the carbohydrate-last vs carbohydrate-first groups 180 mins postmeal. Timing the carbohydrate ingestion can lead to improvements in glycemia and the associated hormone excursions.

Diet Composition Relative to Changes in Cardiometabolic Parameters

The effects of low-carbohydrate diets (≤45% of energy from carbohydrates) vs low-fat diets (≤30% of energy from fat) on metabolic risk factors were compared in a meta-analysis. Compared with participants on low-fat diets, those on low-carbohydrate diets experienced a statistically significantly lower reduction in total cholesterol (-2.7 mg/dL; 95% CI: 0.8, 4.6), and LDL cholesterol (-3.7 mg/dL; 95% CI: 1.0,6.4), but a greater increase in high density lipoprotein (HDL) cholesterol (3.3 mg/dL; 95% CI 1.9,4.7) and a greater decrease in triglycerides (-14.0 mg/dL; 95% CI: -19.4, -8.7). Reductions in body weight, waist circumference and other metabolic risk factors were not significantly different between the two diets.

Foster and colleagues compared patients prescribed a low-carbohydrate diet (<20 g/d for 3 months with subsequent increase in their carbohydrate content once desired weight achieved) compared with a low-fat diet (limited energy intake 1200-1800 kcal/day, <30% fat). Weight loss was approximately 11 kg (11%) at 1 year and 7 kg (7%) at 2 years. There were no differences in weight. During the first 6 months, the low-carbohydrate diet group had greater reductions in biliopancreatic diversion (DBP), triglyceride levels and very-LDL cholesterol levels and lesser reductions in LDL cholesterol levels. The low-carbohydrate diet group had greater increases in HDL cholesterol levels at all time points. Further, Sacks and associates compared four diets with varying nutrient composition; as mentioned above, the targeted percentages of energy derived from fat, protein and carbohydrates in the four diets were 20, 15 and 65%; 20, 25 and 55%; 40, 15, and 45%; and 40, 25 and 35%. He concluded that all the diets reduced risk factors for CV disease and diabetes at 6 months and 2 years. At 2 years, the two low-fat diets and the highest-carbohydrate diet decreased LDL cholesterol levels more than did the high-fat diets or the lowest-carbohydrate diet (low-fat vs high-fat, 5% vs 1%; highest-carbohydrate vs lowest-carbohydrate, 6% vs 1%). The lowest-carbohydrate diet increased HDL cholesterol levels more than the highest-carbohydrate diet (9% vs 6%, P = 0.02). All the diets decreased triglyceride levels similarly, by 12% to 17%. All the diets except the one with the highest carbohydrate content decreased fasting serum insulin levels by 6% to 12%; the decrease was larger with the high-protein diet than with the average-protein diet (10% vs 4%, P=0.07).

Some tips for counseling patients on diet are shown in Figure 8-1, along with visual aids to help patients to make portion sense (Figure 8-2).

Enlarge 

Enlarge 

Physical Activity

Physical activity is an essential component of a weight-loss treatment program. Physical activity influences the composition of weight loss so that a higher proportion of the weight loss is loss of fat as opposed to fat-free mass (or lean muscle) which is metabolically desirable. Exercise may help offset the reduction in resting metabolic rate that results from weight loss itself. Further engaging in physical activity may help facilitate dietary adherence.

The American Heart Association (AHA)/ American College of Cardiology (ACC)/ The Obesity Society (TOS) Guidelines for the Management of Overweight and Obesity in Adults recommend at least 150 minutes of aerobic activity per week (equal to at least 30 minutes per day, most days of the week). This level of activity produces an energy expenditure of approximately 1,000 kcal per week. Physical activity becomes even more critical during the weight-loss maintenance phase. Members of the National Control Weight Registry report maintaining their weight loss by engaging in approximately 1 hour of physical activity per day, expending an average of 2,825 calories per week. In order to maintain weight loss, higher intensity activity (at least 200 to 300 minutes per week) is recommended.

The aim of physical activity is not purely to increase CV activity (eg, walking, running) but it is also important to include resistance training exercises. The Centers for Disease Control and Prevention (CDC) recommend that adults engage in muscle-strengthening activities at least 2 days per week. Resistance training is an effective technique to improve muscle strength and endurance, prevent and modify chronic medical conditions and modify coronary risk factors. Further, strength training can help preserve fat-free mass during weight loss to enhance metabolic rate.

It is often difficult for patients to achieve physical activity goals and time is often a limiting barrier. Research has demonstrated that continuous vs intermittent activity of the same total duration produces equivalent improvements in cardiovascular (CV) health, weight and fasting or postprandial lipemia. Therefore, one may want to counsel patients to focus on achieving small bouts of exercise, multiple times per day (10 minutes of a brisk walk, three to four times daily) as a means to achieve their goal and improve compliance.

Behavioral Modification

Behavioral modification is a critical component in successfully treating obesity and can be used to support any type of dietary intervention. The goal of behavioral treatment is to target maladaptive eating behaviors that contribute to obesity. Various components of a behavioral treatment program may include the following.

Self-Monitoring of Dietary Intake

Individuals with obesity have been shown to underestimate their food intake; thus behavioral treatment programs focus on teaching participants to accurately record the type, amount and total calories of the foods they consume throughout the day. They are also taught how to read food labels and use measuring tools to help improve the accuracy of their food records. Data have shown that individuals who regularly record their food intake lose significantly more weight than those who do so inconsistently.

Trigger or Stimulus Control

Techniques to help control a patient’s environment is crucial in helping support their goal of eating healthy and exercising. As an example, patients may be taught to store food out of sight, limit the number of places they eat to the kitchen or dining table and refrain from eating while engaging in other activities (e.g., working on computer, watching television).

Problem-Solving Techniques

In order to be successful, patients need to be taught problem-solving techniques for when they encounter barriers that limit their ability to be consistent with a healthy diet and exercise plan. The goal is to plan solutions in advance such that the patient can overcome the challenge with ease. As an example, a patient may travel for work and not have access to their usual planned meals; however, with proper education and support, they can create solutions that allow them to overcome an uncertain situation.

Cognitive Restructuring

Individuals attempting to lose weight often exhibit catastrophic thinking that leads them to abandon their weight control efforts. As an example, they may overeat one evening and decide to give up altogether. However, by teaching them to replace these thoughts with more rationale responses, they can recognize a setback as a temporary lapse and continue to move forward.

Relapse Prevention

Techniques for long-term success must focus on relapse prevention, particularly focusing on high-risk situations that may create a set-back (e.g., vacations, illness, or periods of high stress). Behavioral therapy focuses on teaching patients to plan for these events and incorporate them into the long-term weight management plan.

Behavioral treatment may be offered individually or in group sessions (usually 10 to 15 individuals who all begin the treatment program at the same time) and the sessions often last from 60 to 90 minutes. A group format provides social support, and individuals can help one another develop strategies to overcome barriers around achieving the diet and exercise goals. Group sessions are often held weekly during the active weight-loss phase and may taper to biweekly meetings that can help individuals focus on weight maintenance.

Intensive Lifestyle Intervention

The Diabetes Prevention Program (DPP) was designed to determine whether a lifestyle intervention directed at reducing body mass and increasing activity levels, or the medication metformin, would delay or prevent development of diabetes in a high-risk population. The DPP lifestyle intervention was delivered by individual lifestyle coaches. Participants received a 16-week core curriculum over the first 6 months and then had at least one contact monthly for the remainder of the study (at least one in-person visit every 2 months with phone visits as needed to maintain once per month contact) (Table 8-2). Participants who received behavioral treatment achieved a weight loss on average of 7 kg at the end of 1 year (vs 0.1 kg for placebo). Although on average, they regained one third of their weight in years 2 to 3, they were able to reduce their risk of developing T2D by 58% compared with participants treated in the placebo group. Further, even though all groups eventually received some amount of lifestyle intervention, at 10 years, the cumulative incidence of diabetes was lowest in the lifestyle intervention group; this intervention delayed onset of diabetes by 4 years relative to 2 years in the metformin group.

The ongoing Look AHEAD Study is designed to evaluate the effect of an intensive lifestyle intervention (ILI) in people with overweight and T2D and its effect on CV outcomes. Subjects were randomly assigned to ILI or usual care (i.e., diabetes support and education [DSE]). The Look AHEAD intervention is delivered in a group plus individual format by intervention teams that include registered dietitians, behavioral psychologists and exercise specialists. Participants are offered weekly sessions with three group sessions and one individual session per month in the first 6 months and two group sessions and one individual session per month during months 7 through 12, for a total of 42 sessions the first year. In years 2 to 4, participants are offered a minimum of monthly individual sessions and one additional contact by group, phone, mail, or e-mail (Table 8-2). Subjects in the ILI lost 8.6% of their weight at year 1 compared with 0.7% for DSE. At year 4, ILI participants lost an average of 4.7% of initial weight compared with 1.1% for DSE.

Enlarge 

Commercially Available Lifestyle Interventions with Evidence-Based Findings

Weight Watchers

Weight Watchers is a commercially available weight-loss program that emphasizes behavioral modifications. Johnston and colleagues randomized patients to either a self-help program vs enrollment in the Weight Watchers program. The Weight Watchers program allowed for three different avenues to access treatment: either weekly meetings, use of a mobile application, or online Weight Watchers tools. Weights were evaluated at baseline, 3 months and 6 months. Patients enrolled in the Weight Watchers program lost an average of 10.1 lb at 6 months vs 1.3 lb for the self-help group. Importantly, those participants who accessed all of the Weight Watchers platforms more frequently (attended 50% of meetings and used the mobile app and online tools at least 2 times per week) lost on average 19 lb, those using two platforms lost 9.5 lb and those only utilizing one platform lost 9.3 lb.

Jenny Craig

The Jenny Craig weight management program involves one-to-one behavioral counseling, as well as packaged prepared meal plans. Rock and associates evaluated the use of the Jenny Craig program (weekly in person or telephone-based counseling) for 2 years to see how it compared with usual care(where participants received two individualized weight-loss counseling sessions and monthly contacts). The mean weight loss was 7.4 kg (or 7.9% of initial weight) at 24 months for the center-based group, 6.2 kg (or 6.8%) for the telephone-based group and 2 kg (or 2.1%) for the usual care group.

NutriSystem

NutriSystem is a commercially available portion-controlled diet program which provides entrees and snacks to encourage weight loss. Foster and colleagues evaluated participants with obesity and T2D (mean BMI 39, mean A1C 7.5) who were randomly assigned to the portion-controlled diet (NutriSystem) or a DSE program. After the initial 3 months, the NutriSystem group continued on the portion-controlled diet for the remaining 3 months, and the DSE group crossed over to the portion-controlled diet for the remaining 3 months. At 3 months, the NutriSystem lost significantly more weight (7.1% ± 4%) than the DSE group (0.4% ± 2.3%). From 3 to 6 months, the change in weight for both groups was statistically significant. After 3 months, the NutriSystem group had greater reductions in A1C than the DSE group (-0.88 ± 1.1 vs 0.03 ± 1.09; P <0.001). From 3 to 6 months the NutriSystem group had no further change in A1C, while the DSE group showed a significant reduction. The data suggest that patients with obesity and T2D can have significant improvements in weight and glycemic control with the use of a commercially available portion-controlled diet.

Other Commercially Available Interventions

There are a plethora of commercially available lifestyle intervention programs and diets. Some programs promote weight-loss through very low-calorie meal replacements, lower than Weight Watchers, Jenny Craig, or NutriSystem. These regimens result in short-term efficacy, but their long-term efficacy and sustainability are unclear. A large systematic review and meta-analysis collated various commercial weight-loss programs and concluded that 57% of participants lost <5% of their initial body weight, which is not a clinically significant weight-loss outcome and there were high rates of attrition. Although the study concluded that the weight-loss programs do not produce clinically significant results, this conclusion has been challenged with a view that for patients with overweight or obesity even a modest weight decrease under 5% is beneficial. Overall, there are a multitude of commercial weight-loss programs available on the market, but for most there is a lack of efficacy data.

Use of Remote and Mobile Technologies in Behavioral Weight-Loss Programs

Typical behavioral weight-loss programs involve weekly or twice-monthly, face-to-face counseling sessions and can be very effective as described above. However, it can be time and resource intensive and may not be convenient for the patient or provider. Mobile devices have been used successfully to provide dietary guidance and self-monitor weight and other health-related variables. Electronic solutions can deliver a weight loss of up to 5 kg at 6 to 12 months, which is greater than that resulting from no or minimal intervention offered on the internet or in print.

Appel and associates compared two behavioral weight-loss interventions in a primary care setting using remote vs in-person support. Patients were randomized to remote weight-loss support via telephone, a study specific website and email, or offered in-person group and individual sessions along with the other three remote means of support. The groups were evaluated over 24 months. The data showed both groups clinically significant weight loss (-4.6 kg for remote support vs -5.1 kg for in-person) and it did not differ significantly between the groups. The data support the notion that remote support can provide a meaningful alternative weight-loss solution.

Harvey-Benino evaluated an internet-based behavioral obesity treatment program. Subjects were either randomized to an internet-based solution, in-person, or a combination of internet/in-person program (hybrid). Evaluation of the weight loss at 6 months was -5.5 kg, 8 kg and 6 kg for the internet, in-person, and hybrid, respectively. Although weight loss was greater for the in-person program, meaningful weight loss was achieved via remote solutions at a fraction of the cost ($372 vs $706). Further, the addition of in-person to the internet solution did not appear to improve weight-loss outcomes.

Long-term weight maintenance is often one of the most challenging aspects of obesity treatment. Radcliff and colleagues evaluated the use of a telephone vs face-to-face extended-care lifestyle maintenance program after an initial weight-loss program. After 12 months of treatment, weight regain was evaluated in both groups compared with a control. Weight regain was 1.7 kg, 2.1 kg and 3.1 kg for the in-person, telephone and control group, respectively. Both interventions were helpful in keeping weight off, but the telephone format had a lower overall cost.

Intellihealth/Evolve

Intellihealth is a healthcare technology company whose stated mission is to scale and broaden access to effective medical weight management. The approach combines behavioral changes and pharmacotherapy to achieve clinically significant weight loss and sustained weight maintenance. The obesity treatment software platform and app, Evolve, train and support providers to deliver specialized obesity treatment, support patients with education and resources and enable remote patient monitoring (RPM), among other features. Participation in the online program (formerly known as BMIQ), when combined with population health management (without pharmacotherapy), produced a statistically significant greater weight loss as compared to usual care or the online program only. After 12 months, greater than 5% weight-loss was achieved by 32.3%, 14.9% and 20.8% of participants in the combination program, usual care and the online-only program, respectively. The clinical decision support and medication decision support delivered through Evolve provide a structured weight-management intervention for patients as well as obesity treatment recommendations for healthcare providers. The platform aims to bring obesity care to more people by providing online tools for both patients and healthcare providers.

Telemedicine

The SARS-CoV-2 pandemic and the associated quarantine orders have negatively impacted people with obesity, with many reporting increased depression, anxiety, stress eating and decrease in exercise. In order to provide continued care for patients, healthcare providers pivoted to telemedicine instead of in-person visits. A retrospective investigational study explored the effect of virtual visits on weight loss in patients with obesity. The effects of in-person visits, video visits and hybrid visits were compared. After 6 months, the median percent weight change was not significantly different between the three modes of visits, with -4.3%, -5.6% and -5.8% in in-person, hybrid and video groups respectively. A similar pattern was observed for the percent of patients who achieved ≥5% weight loss with 46.4%, 55.3% and 59.3% for in-person, hybrid and video groups, respectively. These results warrant a discussion on incorporating telemedicine visits into the treatment of obesity beyond the pandemic. It seems likely that telemedicine will be just as effective and potentially more convenient than in-person treatment which may help facilitate long-term follow-up which is critical for maintaining weight loss.

Summary

Ultimately, the treatment of obesity requires a long-term intervention. Patients increasingly rely on technology and mobile-based solutions for many of their day-to-day operations. The use of internet-based solutions as a tool in obesity treatment appears to provide a cost-effective alternative to traditional weight-loss interventions.

Comprehensive Lifestyle Interventions

The best diet and behavioral treatment programs typically result in a 10% weight loss during the first 6 months of treatment. Key components to success include three critical components:

• Choosing a diet that appeals to the patients’ preferences so that they can easily adhere to it.
• Incorporating significant physical activity.
• Providing a behavioral treatment plan to reinforce the necessary strategies to maintain weight loss.

Long-term, ongoing contact between the patient and practitioner enhances weight-loss maintenance.