Core Viewpoint - The study reveals the metabolic heterogeneity of sarcopenia and identifies N-methylglycine as a potential risk factor for sarcopenia, suggesting its supplementation could be a new strategy for intervention [3][6][8]. Group 1: Research Findings - The research team conducted a comprehensive plasma metabolomics and lipidomics analysis on two cohorts comprising 1,013 individuals, highlighting a significant decrease in plasma N-methylglycine levels in elderly and sarcopenic patients [6][8]. - In mouse experiments, exogenous supplementation of N-methylglycine was shown to promote anti-inflammatory macrophage polarization, effectively reducing fat accumulation during aging while maintaining skeletal muscle quality at a higher level [3][6]. - The study demonstrated that N-methylglycine activates the GCN2 signaling pathway, enhancing anti-inflammatory macrophage polarization, promoting thermogenesis in adipose tissue, and facilitating muscle regeneration [6][8]. Group 2: Clinical Implications - The research provides scientific evidence for the potential clinical translation of N-methylglycine supplementation as a strategy to prevent sarcopenia in the elderly [3][8]. - The findings suggest that N-methylglycine supplementation can significantly increase fat thermogenesis, reduce white fat, and enhance lean body mass, emphasizing its role in muscle damage repair [8].

Core Viewpoint - The issue of muscle atrophy, previously associated mainly with the elderly, is increasingly affecting younger populations, particularly young women, due to lifestyle choices and societal beauty standards [1][10][12]. Summary by Sections Muscle Atrophy Trends - Muscle atrophy, or sarcopenia, is a progressive loss of skeletal muscle quality and strength, traditionally seen in older adults, but is now emerging in younger women, starting as early as age 35 [10][22]. - The World Health Organization (WHO) reports that approximately one-third of adults globally, around 1.8 billion, are insufficiently active, with a higher proportion of women [1][7]. Factors Contributing to Muscle Loss - Many individuals begin to lose 3% to 5% of lean muscle mass every decade after age 30, with women experiencing this loss earlier and more significantly due to lower baseline muscle mass compared to men [3][10]. - Young women often engage in low-frequency exercise, such as yoga and Pilates, which may not provide sufficient stimulus for muscle growth, leading to rapid declines in muscle strength and endurance when exercise is halted [6][19]. Societal Influences and Beauty Standards - The prevailing beauty standards that favor thinness contribute to a lack of focus on muscle health among young women, who may prioritize weight loss over muscle maintenance [12][15]. - The marketing of health products often emphasizes weight loss rather than muscle gain, further perpetuating the issue [12][13]. Symptoms and Health Implications - Symptoms of muscle loss in young women may be subtle, including mild muscle weakness and increased fatigue, while older women exhibit more pronounced symptoms such as significant muscle weakness and mobility issues [25][22]. - The lack of resistance training and poor nutritional habits, such as insufficient protein intake, exacerbate the risk of developing sarcopenia [19][29]. Recommendations for Prevention - To combat muscle loss, it is recommended that young women engage in resistance training 2-3 times a week, alongside a balanced diet rich in protein and essential nutrients [28][29]. - Incorporating simple exercises and ensuring adequate nutritional intake can help maintain muscle mass and overall health [29][30].