ProteinNEW2026-08

Risk of protein intake deficiency during treatment with GLP-1 and GIP/GLP-1 receptor agonists: considerations for secondary sarcopenia.

Prokopidis Konstantinos, Cacciatore Stefano, Anton Stephen D, Batsis John A — Advances in therapy

Summary

New weight-loss medications, such as GLP-1 drugs, help people lose weight by reducing appetite and overall food intake. This paper highlights a potential concern: the reduced food consumption might also lead to insufficient protein intake, especially for older adults. This could potentially impact muscle health and increase the risk of muscle loss, known as sarcopenia.

AI-generated summary — read the original

Key points

GLP-1 and similar medications help with weight loss by reducing appetite and calorie intake.
Lower overall food intake might inadvertently lead to insufficient total protein consumption.
This protein deficiency could potentially harm muscle health, especially in older adults, increasing the risk of muscle loss.
More research is needed to fully understand the long-term impact on muscle mass and function.

What the study looked at

【研究の狙い】 This paper explored whether newer weight-loss medications, such as GLP-1 and GIP/GLP-1 receptor agonists, could lead to insufficient protein intake and potentially contribute to muscle loss, particularly in older adults. 【研究の方法】 It was a review paper, meaning the authors analyzed existing scientific studies and evidence on these medications and their effects on diet and muscle health, rather than conducting a new experiment with participants. 【研究の結果】 The review found that while these drugs effectively reduce overall calorie intake for weight loss, they might also inadvertently lower the total amount of protein consumed. Even if protein makes up the same *proportion* of a person's diet, the *absolute* amount might fall below what's needed to adequately stimulate muscle protein synthesis in older individuals. The paper notes that more research is needed to confirm if this leads to clinically significant declines in muscle mass or strength.

Dietary takeaway

If you are using GLP-1 or similar medications for weight loss, it's important to pay attention to your protein intake. Prioritizing protein-rich foods at each meal can help ensure you get enough to support muscle health, even with reduced overall food consumption. Keep in mind that this is a review of existing evidence, and more long-term studies are needed to fully understand these effects.

Abstract

Sarcopenia, characterized by the age-related decline in muscle mass and strength, increases the risk of falls, fractures, disability, and mortality. Type 2 diabetes and obesity frequently coexist with sarcopenia, contributing to the growing clinical challenge of sarcopenic obesity. Incretin-based therapies, including glucagon-like peptide-1 (GLP-1) receptor agonists and dual gastric inhibitory polypeptide (GIP)/GLP-1 receptor agonists, induce substantial weight loss through reduced calorie intake and are increasingly prescribed to older adults. However, weight reduction driven by appetite suppression may also decrease absolute protein intake, potentially compromising muscle health in individuals already vulnerable to anabolic resistance. This review examines the available evidence on changes in dietary protein intake during incretin-based therapy and their implications for muscle mass and functional preservation in older adults. Randomized trials suggest that liraglutide generally maintains protein intake as a proportion of total energy (approximately 13.9-17.5%), yet reductions in absolute protein intake may occur due to overall caloric restriction, particularly with more potent appetite suppression. Importantly, even when proportional intake is preserved, reductions in total energy intake may lower absolute protein consumption below levels required to adequately stimulate muscle protein synthesis in older adults. Comprehensive data on dietary intake remain limited, and few studies have systematically evaluated whether such changes translate into clinically meaningful declines in muscle mass, strength, or physical performance. Longer-term trials incorporating detailed dietary assessment, body composition analysis, and functional outcomes are needed to clarify the impact of incretin-based therapies on protein adequacy and muscle health in older adults. A clearer understanding of these interactions is essential to optimize weight management strategies while minimizing the risk of secondary sarcopenia.

View on PubMed →DOI: 10.1007/s12325-026-03750-w