Study
Effect of Branched-Chain Amino Acid Supplementation Alone or Combined With Tryptophan or Methionine on Appetite Control and Related Health Outcomes in Older Adults: Protocol for a Randomized Controlled Trial.
This 110-person BCAA protocol in adults aged 65-80 has no outcome results yet and does not administer rapamycin.
Summary Do these amino-acid supplements reduce appetite or improve health in older adults? Show / hide ↓
Researchers assigned 110 adults aged 65 to 80 to one of four diets for 4 weeks. The groups received no supplement, branched-chain amino acids, or branched-chain amino acids combined with tryptophan or methionine. They planned to measure appetite, food intake, body composition, blood markers, gut bacteria, sleep, and physical performance. About 100 people completed the study, but the researchers were still cleaning and analyzing the data, so no results are available yet. This study does not test rapamycin.
What this means for you: You can ignore this study when deciding whether to buy these supplements, because it has not reported results. It also cannot show whether these products extend life or improve health.
weak evidenceThis is a protocol for a randomised clinical trial of branched-chain amino acids, not a report of intervention outcomes. It recruited 110 adults aged 65 to 80 years with body mass index 20 to 35 kg/m². Participants were assigned to 4 weeks of a controlled diet with no supplement, BCAAs alone, BCAAs plus tryptophan, or BCAAs plus methionine. The stated primary outcomes are self-reported appetite, fibroblast growth factor 21, and energy intake from dietary records. Secondary measures include body composition, cardiometabolic health, gut microbiota, blood biomarkers, sleep, and physical performance. The rationale comes from mouse findings that a particular amino-acid balance, in a high-carbohydrate diet, was associated with greater food intake, obesity, and shorter lifespan; the abstract says those effects were not due to BCAAs alone. No rapamycin is administered in the four described groups. Recruitment ended in November 2025, with 100 participants reported as having completed the study. However, data cleaning and analysis were still in progress, with results expected in 2027. There are therefore no human efficacy, safety, appetite, metabolic, or longevity results to interpret. Any claim about BCAAs, tryptophan, methionine, or rapamycin based on this page would be premature.
The study will clarify the effects of BCAAs alone or with tryptophan or methionine on appetite and related outcomes in older adults.
This is a protocol with no analysed outcome data. It uses a 4-week controlled-diet intervention and no rapamycin; its rationale partly relies on preclinical mouse observations.
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