Research

Energy balance

Very Low-Energy Diets (VLEDs, <800 kcal/d) produce significantly greater short-term weight loss than Low-Energy Diets (LEDs, 800-1800 kcal/d), but this advantage diminishes and becomes statistically non-significant after 12 months.

If you need rapid weight loss (e.g., for surgery or diabetes remission), a medically supervised Very Low-Energy Diet (<800 kcal) works faster than standard diets. However, do not expect this advantage to last beyond a year. The key is using VLED as a short-term tool (12-20 weeks) to achieve a significant initial loss, then carefully transitioning to a sustainable maintenance diet to keep the weight off.

GoodQualifiesHIGH confidence
LEDs prescribed for an average of 12.7 weeks induced a mean loss of 9.7% of initial weight, compared with 16.1% for VLEDs... At >1 year, mean weight loss with LEDs had declined to 5.0%, which was similar to the 6.3% observed with VLEDs.
Ariana M. Chao et al. · Journal of Clinical Investigation · 2021

Why this rating

Based on meta-analyses of RCTs with follow-up of at least 1 year.

Source

Dietary interventions for obesity: clinical and mechanistic findings

Ariana M. Chao et al. · Journal of Clinical Investigation · 2021

DOI 10.1172/jci140065

narrative_reviewCited 241×
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DOI resolved against Crossref · corpus check 2026-06-10

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