Training & movement
A · High confidenceEating less with or without exercise: what happens to fat-free mass
Subject: Effects of Calorie Restriction With and Without Strength, Endurance or Mixed Training on Fat-Free and Skeletal Muscle Mass in Overweight or Obese Individuals: A Systematic Review With Pairwise Meta-Analysis and Network Meta-Analysis of Randomized Controlled Studies
What this means
People who ate less and also exercised lost on average 0.87 kg less fat-free mass than those who only ate less. Exercise prevented nearly half (45.7%) of that loss.
Deller M, Weiershaus J, Held S, Brinkmann C · 2026 · Diabetes, Obesity and Metabolism
What does this rating mean?
Multiple consistent meta-analyses or a position stand. Sufficient basis for a fixed choice in the coaching.
Findings
Adding strength training to calorie restriction better preserved fat-free and skeletal muscle mass compared to calorie restriction alone or calorie restriction plus endurance training. Mixed training was also effective, while endurance alone was less effective for muscle preservation.
Who this applies to
People with overweight or obesity who reduced their calorie intake to lose weight.
Size of the research
34 randomized controlled trials with a total of 1455 participants.
What to keep in mind
Differences between strength, endurance and mixed training were not statistically clear. Only two studies measured skeletal muscle mass itself.
Practical conclusion for REZA
Another reason to never drop resistance training during a diet: it protects muscle mass better than calorie restriction with only cardio or no training at all.
View method and source
Methodology
Meta-analysis
Population
Overweight or obese individuals; calorie restriction with and without exercise
Intervention
Calorie restriction alone vs CR + strength training vs CR + endurance vs CR + mixed training
Outcome measures
Fat-free mass, skeletal muscle mass
Limitations
Heterogeneity; varying CR protocols; varying exercise protocols.
Original source
DOI: 10.1111/dom.70873 · PMID: 42144246
View on PubMed →Effect of exercise training on weight loss, body composition changes, and weight maintenance in adults with overweight or obesity: An overview of 12 systematic reviews and 149 studies
Next study →Resistance training prescription for muscle strength and hypertrophy in healthy adults: a systematic review and Bayesian network meta-analysis
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.