November 01, 2023
4 min read
- Anti-obesity medications and bariatric surgery may lead to adverse events for people with obesity.
- Eating a plant-based diet can induce weight loss without the use of drugs or surgery.
DENVER — Following a plant-based eating plan can help people with obesity lose weight without the use of medications or bariatric surgery, according to a speaker at the Lifestyle Medicine Conference.
Vanita Rahman, MD, clinic director at Barnard Medical Center, Physicians Committee for Responsible Medicine, said anti-obesity medications and bariatric surgery can lead to significant weight loss for people with obesity, but they could also result in adverse events or be cost-prohibitive. Rahman said eating healthier and initiating a plant-based diet can be a less invasive method for people with obesity to lose weight.
“Rather than prescribing expensive drugs or recommending complex surgeries with unclear long-term profiles and side effects, how about we just teach our patients and our loved ones to reach for delicious and nutritious foods,” Rahman said during a presentation.
Eating healthier is a key part of reducing the prevalence of obesity in the U.S., according to Rahman. According to data from the CDC, 42% of American adults have obesity and 32% have overweight. The obesity prevalence is 22.2% for adolescents aged 12 to 19 years, 20.7% for children aged 6 to 11 years and 12.7% for those aged 2 to 5 years.
“The numbers are really alarming,” Rahman said. “Only one out of four Americans has a normal BMI as classified by the BMI scale. That means three out of four Americans are dealing with overweight or obesity. This is a really significant problem.”
Concerns with medications, bariatric surgery
Rahman said newer anti-obesity medications such as semaglutide (Wegovy, Novo Nordisk) and tirzepatide (Mounjaro, Eli Lilly) induced more than 15% weight loss in randomized controlled trials, but there are still some questions. With the STEP 1, STEP 3 and STEP 4 trials that examined semaglutide for adults with obesity, Rahman said, the trials were limited to 68 weeks and no weight data were provided during the 7-week observation period that followed after medications stopped. In the STEP 4 trial, adults received semaglutide were randomly assigned to continue semaglutide or switch to placebo at 20 weeks. Those who switched to placebo regained 6.1 kg from 20 weeks to 68 weeks, whereas those who continued semaglutide lost an additional 7.1 kg of body weight.
Rahman also said there are several potential adverse events that can occur with GLP-1 receptor agonists, including gastrointestinal (GI) symptoms, increase in lipase, increased heart rate and hypoglycemia when a GLP-1 receptor agonist is combined with other medications. Cost is also a concern, Rahman said, for example, once-weekly semaglutide costs an average of $1,616 per month.
Rahman discussed similar concerns when reviewing data from the SURMOUNT-1 trial, where adults with obesity were randomly assigned to once-weekly tirzepatide or placebo for 72 weeks. Tirzepatide induced up to a 22.5% weight loss at 72 weeks for adults receiving the highest dose of 15 mg once weekly. However, Rahman said the side effect profile for tirzepatide is similar to semaglutide and includes GI symptoms, alopecia, loss of appetite, dizziness, injection site reaction and cholecystitis. She also noted that tirzepatide costs $307 per dose.
Rahman said bariatric surgery also confers significant weight loss for people with obesity. In a study published in Annals of Internal Medicine in 2018, Roux-en-Y gastric bypass was associated with a 31% weight loss at 1 year and 26% weight reduction at 5 years, sleeve gastrectomy induced a 25% weight loss at 1 year and a 19% weight reduction at 5 years, and an adjustable gastric band conferred a 14% weight loss at 1 year and 12% weight loss at 5 years.
Despite the benefits, Rahman said, bariatric surgery can be invasive and requires postprocedural monitoring for malabsorption of nutrients.
“We’re talking about a complex invasive surgery with short-term and long-term effects,” Rahman said.
A focus on healthier eating
Guidelines for treating adults with obesity vary based on BMI and comorbidities and may involve medications and bariatric surgery for some. However, Rahman said, regardless of one’s BMI and comorbidity profile, lifestyle changes are an important part of obesity treatment for everyone, especially when examining dietary intake data in the U.S.
Data from the CDC show that 41.8% of adolescents and 39.2% of adults eat less than one serving of fruit per day, and 40.7% of adolescents and 21% of adults eat less than one serving of vegetables per day. A study published in JAMA in 2021 revealed that 67% of daily calories consumed by youths in the U.S. in 2017-2018 come from ultra-processed foods.
“Clearly, we have a lot of work to do,” Rahman said. “This is a public health disaster.”
Changing to a low-fat, plant-based diet could confer benefits for people with obesity without medications or bariatric surgery, according to Rahman. In a study conducted by the Physicians Committee for Responsible Medicine and published in JAMA Network Open in 2020, adults with overweight who ate a plant-based diet for 16 weeks lost a mean 6.4 kg of body weight compared with a 0.5 kg reduction for those eating a control diet. Another study published in the Journal of the American Nutrition Association in 2021 showed adults eating a plant-based diet lost 6 kg of weight at 16 weeks compared with no weight change for adults eating a Mediterranean diet.
Rahman said providers can promote healthier eating habits by instituting programs. She highlighted how the Physicians Committee for Responsible Medicine has a 12-week plant-based weight-loss program in which people attend 75-minute weekly online sessions with a physician and registered dietitian. The sessions include education, a cooking demonstration and practical tips for participants. The Physicians Committee for Responsible Medicine also has a 12-week binge and emotional eating program in which attendees participate in weekly online sessions with a physician, clinical psychologist and registered dietitian. The sessions include education, small-group breakout sessions, weekly homework and practical tips.
“This is not medical care, it’s coaching, education and diet so it’s much easier to run,” Rahman said.
Rahman V. The role of nutritional, pharmacological and surgical approaches in the management of obesity. Presented at: LM2023 Lifestyle Medicine Conference; Oct. 29-Nov. 1, 2023; Denver (hybrid meeting).
Rahman reports no relevant financial disclosures.