Research

Energy balance

Intermittent Energy Restriction (IER) produces weight loss outcomes equivalent to Continuous Energy Restriction (CER) over long-term interventions (≥6 months), with no statistically significant difference in mean weight loss between the two methods.

If you are struggling with the daily rigidity of continuous calorie restriction, try an Intermittent Energy Restriction (IER) approach like the 5:2 diet or Alternate Day Fasting. The evidence shows you will lose the same amount of weight as if you restricted calories every day, but with more flexibility. Focus on consistency over the long term (6+ months) and seek behavioral support to manage the inevitable weight loss plateau that occurs around 6 months.

ModerateRefutesMEDIUM confidence
results indicating neither intermittent or continuous energy restriction being superior with respect to weight loss, 0.084 ± 0.114 (overall mean difference between groups ± standard error; p = 0.458).
Michelle Louise Headland et al. · Nutrients · 2016

Why this rating

Meta-analysis of 9 studies, but limited by high heterogeneity in IER protocols (VLED, 5:2, ADF), small sample sizes in individual trials, and short follow-up durations for many participants.

Source

Weight-Loss Outcomes: A Systematic Review and Meta-Analysis of Intermittent Energy Restriction Trials Lasting a Minimum of 6 Months

Michelle Louise Headland et al. · Nutrients · 2016

DOI 10.3390/nu8060354

Meta-analysis · 9 studiesCited 112×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →