Esther López-García
Professor of Preventive Medicine and Public Health at the Autonomous University of Madrid, President of the Nutrition and Obesity Study Observatory (NAOS), and member of the Nutrition Group of the Spanish Society of Epidemiology
This article summarizes basic research (in experimental animals) on the impact of protein restriction on the development of disease and longevity markers. It is well-written, and the way the review is organized around the possible biological mechanisms that link protein restriction to the effects examined is particularly effective. This work parallels what is known about the effect of calorie restriction on longevity.
It is a bold article because it questions the current recommendation to the general population to increase protein intake to improve health. This recommendation has long been given to pregnant women and older adults, but the 2025 US Dietary Guidelines include it for the general population. In Spain, the 2023 dietary guidelines do not make this recommendation, but the reality is that there is a widespread trend in our country to promote high-protein diets for everyone.
The authors are correct in suggesting that more research is needed to understand whether high-protein diets truly have beneficial effects for the general population. However, their work needs to be supplemented with evidence from observational science and clinical trials in humans, because not everything observed in animal models can be directly translated to humans.