Read the guide · Nutrition
Supplements: What Has Evidence and What Does Not
The list of supplements with a consistent effect in healthy individuals is short, and that is good news: you can learn the essentials in five minutes. Creatine and caffeine have a solid foundation for performance; isolated BCAAs do not build muscle when total daily protein is already adequate; and older adults need more protein per meal to achieve the same effect. Letz does not sell supplements and does not recommend doses — it presents what the literature supports.
Numbers derived from this rule
| Parameter | Range | Weight | Rule |
|---|---|---|---|
| Protein per meal | 0.3–0.55 g/kg/meal | 50% | About 0.4 g/kg per meal across four or more meals maximizes protein synthesis; older adults need the upper end of the range.Distribute protein throughout the day · Protein in older adults |
Rules and studies
- 01Creatine monohydrateCreatine monohydrate is the supplement with the strongest evidence for improving performance in high-intensity efforts and supporting lean mass gains with training, with a favorable safety profile.Only appears as educational information when the user asks; the coach reinforces that the decision belongs to the user and their healthcare provider.
- 02Caffeine and PerformanceCaffeine at doses of 3 to 6 mg/kg improves aerobic performance, strength, and muscular endurance; higher doses do not help and increase adverse effects.The coach only mentions caffeine for informational purposes and advises against its use when logged sleep is already short.
- 03Isolated BCAAs Do Not Build MuscleBranched-chain amino acids on their own do not sustain muscle protein synthesis; whole dietary protein fills this role.When the question comes up, the coach redirects focus toward the daily protein target instead of recommending a supplement.
- 04Protein 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.The per-meal target in the meal plan increases with age; the coach provides reminders for breakfast protein, which is typically the lowest-protein meal.