Obesity treatments have never been more effective than they are today. Access to bariatric surgery and the new obesity medications has transformed clinical obesity care. Nonetheless, as options for the treatment of obesity have rapidly expanded, understanding the long-term effects of these treatments has become more urgent. A major concern has been weight regain among treated patients with obesity.
Weight regain following surgery has been better characterized than weight regain after medication use. Weight regain is very loosely defined as regaining the initially achieved weight loss or some percentage of that weight loss after surgery or GLP-1 use. Some studies have used a definition of “stable weight” defined as ±5 kg for both surgical and nonsurgical patients. Weight regain, also termed weight recurrence, is loosely defined as regaining the initially achieved weight loss or some percentage of that weight loss in excess of 5 kg after surgery or medication use. Weight fluctuation is considered normal. Weight regain has received more attention from bariatric surgeons than internists prescribing GLP-1s. One definition applied to several studies with surgical patients, defines weight regain as an increase of at least 10 kg from nadir weight.
Weight regain after bariatric surgery is common. For example, one report found that up to 76% of patients who underwent a sleeve gastrectomy had significant weight regain, defined as a ≥ 25% increase from nadir weight at 6-year surgery follow-up,. Another study of 2458 adults who underwent bariatric surgery, found that five years after reaching their nadir of weight loss, 50.2% of the Roux-en-Y gastric bypass (RYGB) surgery patients regained more than 15% of their maximal weight loss.
As shown in the figure, a recent systematic review and meta-regression analysis of weight regain in 3236 participants in six clinical trials after the cessation of medication found that 60% of the weight lost during treatment was regained within a year. The impact on health after
obesity medications are stopped is hardly a surprise: hypertension, hyperlipidemia, and glucose intolerance all recur if their medications are discontinued. A more rigorous test analogous to the weight regain in surgical patients is the degree of weight regain attained after several years of continuous GLP-1 therapy.
Together these studies show that weight regain is a common occurrence in both post-surgical patients and after the discontinuation of medications. Based on what we know, continued use of obesity medications is an appropriate approach to the prevention of weight regain. However, in contrast to bariatric surgery, weight regain with prolonged medication use has not been widely described.
Weight regain has implications for health and disease. Weight regain of over 25% of the initial weight reduction is associated with a reversal of cardiometabolic improvements such as blood pressure and cholesterol levels. Weight regain has also been associated with depression and anxiety. The associated feelings of shame, frustration, and worsened mental health are unfortunately met with a lack of guidance by our healthcare system.
Common factors associated with weight regain include dysregulated or maladaptive eating, physiological hormonal changes, and other behavioral patterns. GLP-1 medications are known to reduce appetite and “food noise”, which likely reduces a patient’s independent behavioral skills, leaving them without tools when medication is stopped. Whether bariatric surgery is associated with reduced food noise is uncertain.
Weight regain reflects the need for long-term treatment, not just relatively short-term weight loss. Providers must recognize that weight regain is not attributable to patient “failure” but constitutes a relapse of the chronic disease of obesity. Patients deserve comprehensive, informed, and realistic counseling as they navigate their treatment. Coverage for bariatric surgery and medications should include long term follow-up and recognition and treatment of relapse. Surgical treatment and pharmacotherapy must be recognized as acute interventions; long term therapy requires long term follow-up.