A review of more than 350 studies reports that restricting dietary protein can activate the hormone FGF21 and produce health benefits similar to those seen with calorie restriction. The analysis focuses on how changes in nutrient intake may affect metabolic pathways associated with aging and disease risk. Researchers describe FGF21 as a signaling hormone involved in regulating metabolism, and they summarize evidence suggesting that lower protein intake can raise or trigger FGF21 activity. Across the reviewed studies, the authors characterize protein restriction as potentially promoting longer-term outcomes by influencing processes related to energy balance and metabolic health.
Both outlets describe the review as a synthesis of existing research rather than a single new experiment. While the findings point to a possible mechanistic link—protein restriction leading to FGF21 changes—the reported outcomes are presented as consistent with patterns observed in calorie restriction research. The reports do not specify immediate, individualized dietary guidance, and they characterize the evidence as based on the combined results of many studies.
