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 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. Deltagare were assigned to 4 weeks of a controlled diet with no supplement, BCAAs alone, BCAAs plus tryptophan, or BCAAs plus methionine. The stated primär 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.