Research

Energy balance

Very Low-Calorie Diets (VLCDs) defined as ≤800 kcal/day with high-biologic-value protein produce significantly greater short-term weight loss (1.5-2.5 kg/week) compared to standard low-calorie diets (LCDs, 1200 kcal/day), but long-term weight maintenance is poor and not superior to LCDs when behavioral therapy is included.

If you are severely obese (BMI >30) and have failed standard diets, a VLCD (≤800 kcal/day) with high protein can help you lose weight much faster (approx. 20kg in 12-16 weeks) than a standard 1200 kcal diet. However, you must combine this with behavioral therapy and exercise, as VLCDs alone do not prevent weight regain long-term. This must be done under medical supervision to manage risks like gallstones.

GoodQualifiesHIGH confidence
Weight loss on VLCDs averages 1.5 to 2.5 kg/wk; total loss after 12 to 16 weeks averages 20 kg. These results are superior to standard low-calorie diets of 5020 kJ/d (1200 kcal/d), which lead to weight losses of 0.4 to 0.5 kg/wk and an average total loss of only 6 to 8 kg... Long-term maintenance of weight lost with VLCDs is not very satisfactory and is no better than with other forms of obesity treatment.
Richard L. Atkinson · JAMA · 1993

Why this rating

Based on a comprehensive review of multiple controlled clinical trials and multicenter evaluations by a National Task Force.

Source

Very Low-Calorie Diets

Richard L. Atkinson · JAMA · 1993

DOI 10.1001/jama.1993.03510080071034

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DOI resolved against Crossref · corpus check 2026-06-10

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