Research

Energy balance

Very-low-calorie diets (VLCDs, 400-800 kcal/d) produce significantly greater initial weight loss than low-calorie diets (LCDs, 800-1200 kcal/d), but long-term weight maintenance success is determined by active follow-up (behavioral therapy, nutrition education, exercise) rather than the initial diet intensity.

To use a VLCD effectively, do not just rely on the low calories. You must pair the 400-800 kcal diet with active behavioral therapy, nutritional education, and exercise. This combination is what leads to sustained weight loss, whereas VLCD alone often fails long-term.

GoodQualifiesHIGH confidence
VLCDs and low-calorie diets with an average intake between 400 and 800 kcal do not differ in body weight including VLCD treatment with long-term weight maintenance... There is evidence that a greater initial weight loss using VLCDs with an active follow-up weight-maintenance program, including behavior therapy, nutritional education and exercise, improves weight maintenance.
Wim H. M. Saris · Obesity Research · 2001

Why this rating

Based on a review of 9 RCTs and meta-analyses, though long-term data shows high variability.

Source

Very‐Low‐Calorie Diets and Sustained Weight Loss

Wim H. M. Saris · Obesity Research · 2001

DOI 10.1038/oby.2001.134

narrative_reviewCited 226×
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DOI resolved against Crossref · corpus check 2026-06-10

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