Research
Macro partitioning
Sleep restriction during a caloric deficit reduces fat loss and increases fat-free mass loss compared to adequate sleep, making weight loss less effective.
If you are dieting, ensure you are getting enough sleep. Even if your total weight loss looks similar, sleeping less causes your body to break down more muscle and save less fat. This makes it harder to keep the weight off and lowers your metabolic rate. Aim for 7-8 hours of sleep to maximize fat loss.
ModerateSupportsMEDIUM confidence
During SR, weight loss was comprised of more fat-free mass and less fat mass... participants lost less than half as much fat mass as they did during the normal sleep phase.
Why this rating
Based on a small inpatient study (n=10) and secondary analysis of larger studies.
Source
Sleep–obesity relation: underlying mechanisms and consequences for treatment
Marie‐Pierre St‐Onge · Obesity Reviews · 2017
DOI 10.1111/obr.12499
narrative_reviewCited 235×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Sleep restriction (SR) increases energy intake by 300–550 kcal/day and alters hormonal signaling (increased ghrelin, decreased leptin, reduced GLP-1) and brain reward network activity, leading to a positive energy balance and weight gain.Good
- Sleep extension in short sleepers reduces appetite, particularly for sweet and salty foods, and increases daytime physical activity, supporting weight management.Limited
Related findings · Macro partitioning
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- Resistance exercise training combined with sufficient dietary protein intake acts synergistically to maximize skeletal muscle hypertrophy, with protein intake saturating around 1.6 g/kg/day for general populations and potentially requiring 2.0-2.2 g/kg/day for resistance-trained individuals.Strong
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