Nutrition · Moderate evidence
Rate of weight loss
Losing weight slowly, at around 0.5 to 1% of body weight per week, better preserves lean mass, strength, and metabolic rate compared to rapid weight loss.
Controlled trial in athletes and meta-analysis · 2 sources · 2 min
What the studies show
- Athletes losing 0.7% of body weight per week gained lean mass and strength; at 1.0% per week, they did not.
- Gradual weight loss reduced more fat and better preserved resting metabolic rate compared to rapid weight loss.
- Lean mass did not differ significantly between rates in the meta-analysis, but fat mass and metabolic rate did.
How Letz applies it
The default calorie deficit in Letz is 15% of energy expenditure, capped between 250 and 500 kcal, and weight forecasting uses ranges rather than a promised date.
Numbers derived from this rule
| Parameter | Range | Weight | Rule |
|---|---|---|---|
| Calorie deficit | 10–25 % of expenditure1 variant by context | 80% | Deficit of 10 to 25% of expenditure, aiming for a loss of 0.5 to 1% of body weight per week; faster rates cost lean mass and metabolism.Rate of weight loss · Higher Protein Intake During a Calorie Deficit · Weight change is dynamic |
| Weekly weight change | 0.5–1 % of body weight/week1 variant by context | 60% | Lose 0.5 to 1% of body weight per week; gain up to about 0.5% per week when the goal is mass.Rate of weight loss · Calorie surplus for muscle gain |
Who it applies to
Overweight adults or athletes who need to reduce body fat while maintaining performance.
Limits
Gradual weight loss requires more weeks of adherence; the comparison in athletes used deficits of 19% and 30%.
Sources
- Garthe et al., International Journal of Sport Nutrition and Exercise Metabolism, 2011 DOI 10.1123/ijsnem.21.2.97
- Ashtary-Larky et al., British Journal of Nutrition, 2020 DOI 10.1017/S000711452000224X
More in Nutrition
- Protein and Training AdaptationSufficient protein can support gains in lean mass and strength alongside training; the response varies and does not increase indefinitely with higher intakes.
- Higher Protein Intake During a Calorie DeficitIn a deficit, higher protein protects lean mass and can even allow muscle gain alongside intense training; the effective range rises to approximately 1.6 to 2.4 g/kg.
- Distribute protein throughout the dayDividing protein into servings of around 0.4 g/kg across four or more meals stimulates protein synthesis more than concentrating everything into one or two.
- Protein in older adultsOlder adults need more protein per meal to stimulate muscle synthesis; consensus guidelines recommend 1.0 to 1.2 g/kg/day or more for those who train.