Research

Energy balance

An energy deficit of approximately 500 kcal per day completely prevents lean mass gains from resistance training.

If your goal is to build muscle while losing fat, a 500 kcal daily deficit will likely result in zero muscle gain. You must either reduce the deficit below 500 kcal/day or accept that muscle growth will be stalled while you lose fat.

GoodSupportsMEDIUM confidence
an energy deficit of ~500 kcal day−1 prevented gains in LM.
Chaise Murphy et al. · Scandinavian Journal of Medicine and Science in Sports · 2021

Why this rating

Derived from meta-regression of multiple studies, though limited by the lack of data on deficits >1000 kcal/day.

Source

Energy deficiency impairs resistance training gains in lean mass but not strength: A meta‐analysis and meta‐regression

Chaise Murphy et al. · Scandinavian Journal of Medicine and Science in Sports · 2021

DOI 10.1111/sms.14075

Meta-analysis · 59 studiesCited 53×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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