Research

Energy balance

Intermittent energy restriction (IER) reduces body weight and fat mass compared to a usual diet, with effects on weight loss being similar to continuous energy restriction (CER).

If you struggle with daily calorie counting, try Intermittent Energy Restriction (IER). This involves restricting calories to 20-25% of your normal intake (or fasting completely) on 1-2 days per week (like the 5:2 diet) or every other day (ADF), while eating normally on other days. This approach reduces body weight and fat mass just as effectively as continuous daily restriction, offering more flexibility.

ModerateSupportsLOW confidence
IER improves anthropometric outcomes and intermediate disease markers when compared to a usual diet. The effects of IER on weight loss are similar to weight loss achieved by CER.
Lukas Schwingshackl et al. · Critical Reviews in Food Science and Nutrition · 2020

Why this rating

The study is a systematic review and meta-analysis of 17 RCTs, but the certainty of evidence for weight loss vs usual diet is rated 'low' due to risk of bias and imprecision.

Source

Impact of intermittent energy restriction on anthropometric outcomes and intermediate disease markers in patients with overweight and obesity: systematic review and meta-analyses

Lukas Schwingshackl et al. · Critical Reviews in Food Science and Nutrition · 2020

DOI 10.1080/10408398.2020.1757616

Meta-analysis · 17 studiesCited 52×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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