Research

Energy balance

Medically supervised very-low-calorie diet (VLCD) programs (e.g., OPTIFAST, Health Management Resources) produce significant short-term weight loss (15-25%) but are associated with high attrition and substantial long-term weight regain (maintaining only 5-9% loss at 1-4 years).

Medically supervised VLCDs like OPTIFAST or Health Management Resources can help you lose 15-25% of your body weight in 3-6 months, but they are expensive and rigid. Most people drop out, and those who finish often regain half the weight within 1-2 years unless they strictly follow a maintenance plan. Use this only if you have medical complications requiring supervision and are prepared for the cost and effort of long-term maintenance.

ModerateQualifiesMEDIUM confidence
One randomized trial and several case series of medically supervised very-low-calorie diet programs found that patients who completed treatment lost approximately 15% to 25% of initial weight. These programs were associated with high costs, high attrition rates, and a high probability of regaining 50% or more of lost weight in 1 to 2 years.
Adam Gilden Tsai et al. · Annals of Internal Medicine · 2005

Why this rating

Based on 1 RCT and several case series; the authors note these represent a 'best-case scenario' due to lack of dropout adjustment.

Source

Systematic Review: An Evaluation of Major Commercial Weight Loss Programs in the United States

Adam Gilden Tsai et al. · Annals of Internal Medicine · 2005

DOI 10.7326/0003-4819-142-1-200501040-00012

systematic_reviewCited 812×
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DOI resolved against Crossref · corpus check 2026-06-10

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