What’s the Best Approach for Sustained Weight Loss?

Given that more than 100 million US adults have obesity, including 22 million with severe obesity, physicians regularly see patients with the condition in their practices.

Fortunately, doctors have more tools than ever to help their patients. But the question remains: Which method is the safest and most effective? Is it diet and lifestyle changes, one of the recently approved anti-obesity medications (AOMs), bariatric surgery, or a combination approach?

There are no head-to-head trials comparing these three approaches, said Vanita Rahman, MD, clinic director of the Barnard Medical Center, Washington, DC, at the International Conference on Nutrition in Medicine, sponsored by the Physicians Committee for Responsible Medicine.

Instead, doctors must evaluate the merits and drawbacks of each intervention and decide with their patients which treatment is best for them, she told Medscape Medical News. When she sees patients, Rahman shares the pertinent research with them, so they are able to make an informed choice.

Looking at the Options

In her presentation at the conference, Rahman summarized the guidelines issued by the American Heart Association/American College of Cardiology/The Obesity Society for Management of Overweight and Obesity in Adults and the American Association of Clinical Endocrinologists and American College of Endocrinology Comprehensive Clinical Practice Guidelines For Medical Care of Patients with Obesity, including lifestyle changes, AOMs, and bariatric surgery (Table 1).

As shown, the current clinical guidelines offer recommendations that consider such factors as the patient’s BMI and presence of one or more comorbidities. Generally, they begin with lifestyle changes for people with overweight, the possibility of an AOM for those with obesity, and bariatric surgery as an option for those with severe obesity-related complications.

“In obesity, we traditionally thought the process was ‘either-or’ — either lifestyle or surgery or medication — and somehow lifestyle is better,” Sheethal Reddy, PhD, a psychologist at the Bariatric Center at Emory University Hospital Midtown, Atlanta, told Medscape Medical News.

Now physicians often use a combination of methods, but lifestyle is foundational to all of them, she said.

“If you don’t make lifestyle changes, none of the approaches will ultimately be effective,” said Reddy, who also is an assistant professor in the Division of General and GI Surgery at Emory School of Medicine, Atlanta.

Lifestyle changes don’t just involve diet and nutrition but include physical exercise.

“Being sedentary affects everything — sleep quality, appetite regulation, and metabolism. Without sufficient exercise, the body isn’t functioning well enough to have a healthy metabolism,” Reddy said.

How Durable Are the Interventions?

Although bariatric surgery has demonstrated effectiveness in helping patients lose weight, many of them regain some or most of it, Rahman said.

A systematic review and meta-analysis found weight regain in 49% of patients who underwent bariatric surgery patients, with the highest prevalence after Roux-en-Y gastric bypass.

Another study of approximately 45,000 patients who underwent bariatric surgery found differences not only in the percentage of total weight loss among Roux-en-Y gastric bypass, sleeve gastrectomy, and adjustable gastric band procedures but also in how much of that weight stayed off between 1 and 5 years following the procedure (Table 2).

Weight regain also is a risk with AOMs, if they’re discontinued.

The STEP 1 trial tested the effectiveness of semaglutide — a glucagon-like peptide 1 (GLP-1) receptor agonist — as an adjunct to lifestyle intervention for weight loss in patients with obesity or with overweight and at least one comorbidity but not diabetes. Mean weight loss with semaglutide was 17.3% but that figure dropped 11.6 percentage points after treatment was discontinued.

Other studies also have found that patients regain weight after GLP-1 discontinuation.

Tirzepatide, a GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) combination, has shown efficacy with weight reduction, but patients experienced some weight regain upon discontinuation. In one study, patients experienced a mean weight loss of 20.9% after 36 weeks of tirzepatide. In the study’s subsequent 52-week double-blind, placebo-controlled period, patients who stopped taking the medication experienced a weight regain of 14%, whereas those who remained on the medication lost an additional 5.5% of weight.

GLP-1 and GLP-1/GIP medications do not address the factors that contribute to overweight and obesity, Rahman said. “They simply suppress the appetite; therefore, weight gain occurs after stopping them.”

Patients may stop taking anti-obesity drugs for a variety of reasons, including side effects. Rahman noted that the common side effects include nausea, vomiting, and constipation, whereas rare side effects include gastroparesis, gallbladder and biliary disease, thyroid cancer, and suicidal thoughts. GLP-1 and GLP-1/GIP medications also carry a risk for non-arteritic anterior ischemic optic neuropathy, she said.

Moreover, health insurance does not always cover these medications, which likely affects patient access to the drugs and compliance rates.

“Given the side effects and frequent lack of insurance coverage, significant questions remain about long-term safety and feasibility of these agents,” Rahman said.

What About Nutritional Approaches?

The lifestyle interventions in the semaglutide and tirzepatide studies included 500 kcal/d deficit diets, which is difficult for people to maintain, noted Rahman, who is the author of the book Simply Plant Based: Fabulous Food for a Healthy Life.

Additionally, bariatric surgery has been associated with long-term micronutrient deficiencies, including deficiencies in vitamins A, D, E, K, B1, and B12, as well as folate, iron, zinc, copper, selenium, and calcium, she said.

The best approach to food from a patient compliance standpoint and to avoid nutrient deficiencies is a whole-food, plant-based diet, Rahman said. She advocates this nutritional approach, along with physical activity, for patients regardless of whether they’ve selected lifestyle intervention alone or combined with an AOM or bariatric surgery to address obesity.

Rahman cited a 5-year heart disease study comparing an intensive lifestyle program involving a vegetarian diet, aerobic exercise, stress management training, smoking cessation, and group psychosocial support to treatment as usual. Patients in the lifestyle group lost 10.9 kg at 1 year and sustained weight loss of 5.8 kg at 5 years, whereas weight in the control group remained relatively unchanged from baseline.

She also pointed to the findings of a study of patients with obesity or with overweight and at least one comorbidity that compared standard care with a low-fat, whole-food, plant-based diet with vitamin B12 supplementation. At 6 months, mean BMI reduction was greater in the intervention group than the standard care group (−4.4 vs −0.4).

In her practice, Rahman has seen the benefits of a whole-food, plant-based diet for patients with obesity.

If people are committed to this type of dietary approach and are given the tools and resources to do it effectively, “their thinking changes, their taste buds change, and they grow to enjoy this new way of eating,” she said. “They see results, and it’s a lifestyle that can be sustained long-term.”

Addressing Drivers of Weight Gain

Patients also need help addressing the various factors that may contribute to overweight and obesity, including overconsumption of ultra-processed foods, substandard nutritional quality of restaurant foods, increasing portion sizes, distraction during eating, emotional eating, late-night eating, and cultural/traditional values surrounding food, Rahman noted.

Supatra Tovar, PsyD, RD, a clinical psychologist with a practice in Pasadena, California, agreed that identifying the reasons for weight gain is critical for treatment.

“If you’re not addressing underlying issues, such as a person’s relationship with food, behaviors around food, the tendency to mindlessly eat or emotionally eat or eat to seek comfort, the person’s weight problems won’t ultimately be fully solved by any of the three approaches — dieting, medications, or bariatric surgery,” she said.

Some of her patients “engage in extreme dieting and deprivation, and many who use medications or have had bariatric surgery hardly eat and often develop nutritional deficiencies,” said Tovar, author of the book Deprogram Diet Culture: Rethink Your Relationship with Food, Heal Your Mind, and Live a Diet-Free Life.

The key to healthy and sustained weight loss is to “become attuned to the body’s signals, learn how to honor hunger, stop eating when satisfied, and eat more healthful foods, such as fruits and vegetables, whole grains, lean proteins — especially plant-based proteins — and the body gives signals that this is what it wants,” she said.

Tovar doesn’t give her clients a specific diet or set of portions.

“I teach them to listen to their bodies,” she said. “They’ve lost significant amounts of weight and continued to keep it off because they’ve done this kind of work.”

When Lifestyle Changes Aren’t Enough

For many patients, lifestyle interventions are insufficient to address the degree of overweight and obesity and common comorbidities, said W. Timothy Garvey, MD, associate director and professor, Department of Nutrition Sciences, School of Health Professions, University of Alabama at Birmingham.

“Of course, nutritional approaches are very important, not only for weight but also for general health-related reasons,” said Garvey, lead author of the 2016 American Association of Clinical Endocrinologists obesity guidelines. “We’ve seen that the Mediterranean and some plant-based diets can prevent progression from prediabetes to diabetes and improve other parameters that reflect metabolic health.”

However, it’s “not common that patients can follow these diets, lose weight, and keep it off,” Garvey cautioned. Up to 50% of weight that’s lost through lifestyle changes is typically regained by 1-year follow-up, with almost all remaining lost weight subsequently regained in the majority of individuals because the person “has to fight against pathophysiological process that drive weight regain,” he noted.

Weight-loss medications can address these pathophysiologic processes by “addressing interactions of satiety hormones with feeding centers in the brain, suppressing the appetite, and making it easier for patients to adhere to a reduced-calorie diet.”

Garvey views the weight-loss medications in the same light as drugs for diabetes and hypertension, in that people need to keep taking them to sustain the benefit.

There’s still a role for bariatric surgery because not everyone can tolerate the AOMs or achieve sufficient weight loss.

“Patients with very high BMI who have trouble ambulating might benefit from a combination of bariatric surgery and medication,” Garvey said.

While some side effects are associated with AOMs, being an “alarmist” about them can be detrimental to patients, he warned.

“We’re treating obesity, which is a serious disease, and we need to employ all the tools that we can,” Garvey said.

Rahman and Tovar are authors of books about weight loss. Reddy reported no relevant financial relationships. Garvey is a consultant on advisory boards for Boehringer Ingelheim, Eli Lilly, Novo Nordisk, Pfizer, Fractyl Health, Alnylam Pharmaceuticals, Inogen, Zealand, Allurion, Carmot/Roche, Terns Pharmaceuticals, Neurocrine, Keros Therapeutics, and Regeneron. He is the site principal investigator for multi-centered clinical trials sponsored by his university and funded by Novo Nordisk, Eli Lilly, Epitomee, Neurovalens, and Pfizer. He serves as a consultant on the advisory board for the nonprofit Milken Foundation and is a member of the Data Monitoring Committee for phase 3 clinical trials conducted by Boehringer-Ingelheim and Eli Lilly.

Batya Swift Yasgur, MA, LSW is a freelance writer with a counseling practice in Teaneck, New Jersey. She is a regular contributor to numerous medical publications, including Medscape Medical News and WebMD, and is the author of several consumer-oriented health books, as well as Behind the Burqa: Our Lives in Afghanistan and How We Escaped to Freedom (the memoir of two brave Afghan sisters who told their story).