The benchmark for most trials for weight loss (WL) medications or devices seeking approval by the Federal Drug Administration (FDA) is a 5% TBWL in at least 35% of participants. Average initial BMI in most trials is below 40kg/m2. A 10% TBWL is not a usual FDA benchmark for WL trials. This study aims to assess the feasibility of a 10% or greater TBWL in morbidly obese patients with only intensive lifestyle intervention (ILI).


1470 patients who participated in our medical weight loss program between January 2016 and March 2019 and had at least 30 days of follow-up were included. ILI included a structured curriculum-based nutritional, exercise and behavior modification program that included individual and group visits with physicians, dietitians and behavior health specialists. A low-calorie, high-protein diet with supplements and food choices was used. Patients were educated that a 10% TBWL is the goal.


Mean (SD) initial BMI was 42.1 (10.3) Kg/m2. 1308/1470 (89%) patients lost weight. Mean %TBWL, WL, waist and neck circumference for all patients were 6.6% (6.0), 7.7 (8.0) kg, 7.6 + (8.1) cm and 1.4 (2.9) cm respectively. Mean follow-up was 5.8 (5.1) months. 810/1470 (55.1%) and 373/1470 (25.4%) of patients achieved at least a 5% or 10% TBWL respectively. Patients with ≥10%TBWL had a higher initial BMI (43.4 vs. 41.7 kg/m2, p<.0001) and a longer follow-up (210.7 vs. 162.8 days, p<.0001).A 10% TBWL was associated with greater reduction of Hba1c (0.42 vs. 0.38, p=0.014).


A 10% TBWL with ILI is feasible in a significant percentage of morbidly obese individuals participating in a real world high-volume WMP. Raising the bar of expected WL can help patients achieve a better outcome.