Nutrition
B · Reasonable confidenceIntermittent fasting alongside strength training and body fat
Subject: Effects of intermittent fasting combined with resistance training on body composition: a systematic review and meta-analysis
What this means
With intermittent fasting alongside strength training, participants lost on average 2.08 kg more body weight and 1.36 kg more fat mass than without fasting. Fat-free mass stayed similar.
Ashtary-Larky D, Bagheri R, Tinsley GM, Asbaghi O, Paoli A, Moro T · 2021 · Physiology & Behavior
What does this rating mean?
A solid systematic review with caveats, or consistent indications with a limited scope.
Findings
Intermittent fasting produced similar body-composition changes to non-fasting diets when protein and calories were matched, alongside resistance training. Intermittent fasting is a viable strategy but not superior to continuous energy restriction; adherence remains the key determinant.
Who this applies to
People doing strength training. Age, sex and training experience are not reported in the abstract.
Size of the research
Eight studies with a total of 221 participants.
What to keep in mind
This is a small number of studies with few participants. The abstract does not say how long the studies lasted or which fasting schedules were used.
Practical conclusion for REZA
For clients considering fasting: it's a valid approach but not superior to continuous calorie restriction — REZA leaves the choice to whichever the client will actually stick to.
View method and source
Methodology
Meta-analysis
Population
Studies comparing IF + RT vs non-IF + RT
Intervention
IF + RT vs non-IF diet + RT
Outcome measures
Body composition (fat mass, lean mass)
Limitations
Limited studies; heterogeneity in IF protocols; varying RT protocols.
Original source
DOI: 10.1016/j.physbeh.2021.113453 · PMID: 33984329
View on PubMed →This information is general education about scientific research. It is not personal medical advice and does not replace diagnosis or treatment by a doctor or other healthcare professional. If you have symptoms, a medical condition or take medication, consult your GP or treating professional before changing your training or nutrition.