Breakfast helps you lose weight. Right?

Meta-analysis of randomised trials. 13 trials. trials lasted 24 hours to 16 weeks; mean follow-up 7 weeks for weight (range 2-16 weeks), 2 weeks for calorie intake (24 h to 6 weeks).

Many trials, added up. In each one, chance decided who did what.

Who: Adults in the US, UK and Japan (1 trial); mix of normal weight, overweight and obesity (5 trials only overweight/obesity); mostly community-based, plus hospital workers and students; many trials women-only. Excluded children/adolescents and people with diabetes or binge eating disorder

• Weight+½ kgbreakfast group
• Food in a dayMorebreakfast group
• Skippers laterNo extrafood

The tests were short and not great.

More to know, from our read of the paper:

• Authors rate the quality of evidence as LOW: all 13 trials were at high risk of bias (mainly no blinding of participants/personnel and outcome assessors; sequence generation and allocation concealment unclear in most)
• Very short trials: mean 7 weeks for weight and 2 weeks for calories, so nothing can be said about long-term weight; the authors explicitly call the extra ~260 kcal something that 'could lead to' weight gain, not proof that it does
• The weight difference is small (0.44 kg, CI 0.07 to 0.82) and the lower CI bound is close to zero; subgroup estimates by BMI were not individually significant
• Calorie result is highly inconsistent (I²=80%); two trials in hospital workers/students found the opposite (less total intake with breakfast). Several trials used self-reported 7-day food diaries
• Missing standard errors were imputed for all crossover trials (no paired analyses reported), though results held in sensitivity analyses

Scientists added up 13 tests where grown-ups were split by chance: eat breakfast or skip it (a meta-analysis of 13 randomised trials in the US, UK and Japan). The breakfast groups ended up about 0.44 kg heavier and ate about 260 more calories a day. The skippers did not eat extra later in the day. But the tests were short (about 7 weeks for weight) and the authors rate the evidence as low quality, so this is not proof that skipping is healthy.

We read the abstract and the full text of this paper and checked every number on this page against it (19 facts, checked on 2026-10-03). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.