Nutrition, Medications, or Weight Loss Surgery: Which Method is Most Effective for Long-Term Weight Management?

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.

Thankfully, physicians now have access to a wider array of tools to assist their patients than ever before. However, a critical question persists: What is the safest and most effective method? Should it be dietary and lifestyle modifications, one of the newly sanctioned anti-obesity drugs (AOMs), bariatric surgery, or an integrated strategy that combines multiple approaches?

There are no head-to-head trials comparing these three approaches, said Dr. Vanita Rahman, 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.

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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.

Exploring the Choices

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).

The existing clinical guidelines take into account various factors, including the patient's BMI and the existence of additional comorbidities. Typically, these guidelines advocate for lifestyle modifications for individuals who are overweight, suggest the option of an Anti-Obesity Medication (AOM) for those classified as obese, and present bariatric surgery as a viable choice for patients facing severe complications related to obesity.

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

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According to her, doctors frequently employ various techniques, yet lifestyle remains the cornerstone of all these approaches.

“Reddy, an assistant professor in the Division of General and GI Surgery at Emory School of Medicine in Atlanta, stated, ‘Without implementing lifestyle changes, none of the strategies will be truly effective in the long run.’”

Transforming your lifestyle encompasses more than just dietary adjustments; it also involves incorporating physical activity into your routine.

“Leading a sedentary lifestyle impacts various aspects of health, including sleep quality, appetite control, and metabolic function. According to Reddy, without adequate physical activity, the body struggles to maintain a healthy metabolism.”

How Long-Lasting Are the Interventions?

Rahman noted that while bariatric surgery has proven to be effective in assisting patients with weight loss, a significant number of them end up regaining a portion or even the entirety of the weight they lost.

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).

Discontinuing AOMs can also pose a risk of weight regain.

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.

According to Rahman, GLP-1 and GLP-1/GIP medications fail to tackle the underlying causes of overweight and obesity. "These medications only curb appetite, which means that weight gain can happen once they are discontinued," he explained.

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.

"Rahman stated that due to the potential side effects and the common absence of insurance coverage, there are still major concerns regarding the long-term safety and practicality of these treatments."

What Are the Nutritional Strategies?

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.

According to Rahman, the most effective way to ensure patient compliance and prevent nutrient deficiencies is through a whole-food, plant-based diet. She supports this dietary method, along with regular physical activity, for patients, irrespective of whether they choose to focus solely on lifestyle changes or incorporate an anti-obesity medication (AOM) or bariatric surgery to tackle 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 observed the positive effects of a whole-food, plant-based diet on patients struggling with obesity.

When individuals fully embrace this dietary method and are equipped with the necessary tools and resources, “their mindset shifts, their palate evolves, and they come to appreciate this new eating style,” she explained. “They experience positive outcomes, making it a sustainable lifestyle over the long haul.”

Tackling Factors Contributing to 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, Doctor of Psychology, Registered Dietitian, a clinical psychologist based in Pasadena, California, emphasized the importance of understanding the underlying causes of weight gain as a key component of effective treatment.

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"She emphasized that without tackling the root causes, like an individual's relationship with food, their eating habits, and the tendency to eat mindlessly or for emotional comfort, no approach—be it dieting, medication, or bariatric surgery—will completely resolve a person's weight issues."

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.

According to her, the secret to achieving healthy and lasting weight loss lies in “tuning into your body’s cues, recognizing and respecting hunger, ceasing to eat once you feel full, and opting for more nutritious options like fruits, vegetables, whole grains, and lean proteins — particularly those derived from plants — as the body indicates that these are its preferred choices.”

Tovar does not provide her clients with a defined meal plan or specific portion sizes.

"I guide them in tuning into their bodies," she explained. "They've shed considerable weight and maintained their progress thanks to this approach."

When Lifestyle Adjustments Fall Short

According to Dr. W. Timothy Garvey, associate director and professor in the Department of Nutrition Sciences at the University of Alabama at Birmingham, many patients find that lifestyle changes alone do not adequately tackle their significant issues with overweight, obesity, and related health conditions.

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“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 perceives weight-loss medications similarly to those used for diabetes and hypertension, emphasizing that individuals must continue using them to maintain their advantages.

Bariatric surgery continues to play an important role, as not everyone is able to handle AOMs or achieve adequate weight loss results.

Garvey stated that individuals with a significantly elevated BMI who experience difficulties in walking could potentially gain advantages from a treatment plan that includes both bariatric surgery and medication.

He cautioned that while certain side effects are linked to AOMs, adopting an overly alarmist attitude towards them could harm patients.

Garvey stated, "Obesity is a critical illness that we are addressing, and it's essential for us to utilize every available resource."

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).