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Notable Publication: Weight Regain after Total Meal Replacement Very Low-calorie Diet Program with and without Anti-obesity Medications

March 26, 2024

In collaboration with current and former medical residents, researchers from the UPMC Division of Endocrinology and Metabolism recently published a notable report in Obesity Science and Practice that explored the effects of adjuvant anti-obesity medications (AOMs) on weight loss and weight regain within a comprehensive lifestyle program.

Faculty researchers from the Division included Hussain Mahmud, MD, clinical associate professor of Medicine and EDM Fellowship associate program director, and David Rometo, MD, clinical associate professor of Medicine and clinical lead of the Endocrine Obesity Unit and Weight Management Program. Dr. Rometo was the corresponding author of the study.

Background: It’s believed that individuals who follow a very low-calorie diet (VLCD) and practice total meal replacement (TMR) can see significant short-term weight loss benefits. Anti-obesity medications (AOMs) have also shown potential as adjunctive treatments for weight loss when combined with VLCDs.

Methods: Researchers conducted a retrospective study of patients with obesity enrolled in VLCD/TMR programs, specifically the OPTIFAST® program. OPTIFAST® is a medically supervised weight loss program that includes three phases of weight loss:

  • Active weight loss.
  • A transition phase.
  • A maintenance phase.

Researchers assessed the 6-month and 18-month weight loss outcomes across 206 patients, calculating the percentage of lost weight regained at 18 months among individuals with obesity enrolled at an institution's VLCD/TMR program. Additionally, a comparison was made between the results of individuals receiving AOM and those not receiving AOM.

Results: 139 patients received no AOM (AOM-), while 67 received AOMs (AOM+). The total body weight loss percentages at 6 and 18 months were -17.87% ± 7.02 and -12.10% ± 11.56, respectively.

There was no significant difference in six-month weight loss between the AOM groups. However, the AOM+ group exhibited lower weight regain (3.29 kg ± 10.19 vs. 7.61 kg ± 11.96) and weight regain percentage (31.5% ± 68.7 vs. 52.16% ± 64.4) compared with the AOM- group.

Conclusion: Results from this study demonstrated the potential of AOMs and VLCD/TMR as effective strategies for long-term weight management in individuals with obesity.

View the full study.


Cifuentes L, Galbiati F, Mahmud H, Rometo D. Weight regain after total meal replacement very low-calorie diet program with and without anti-obesity medications. Obes Sci Pract. 2024;e722.