Sexual dimorphisms in juvenile development under nutritionnal stress

Nutrition is a fundamental regulator of juvenile development. The persistently high global prevalence of childhood undernutrition and consequent stunting underscores the urgent need to better understand how nutritional status shapes developmental trajectories. Biological sex has recently emerged as a key risk factor for stunting, with boys consistently exhibiting greater vulnerability. This review examines the biological basis of sex differences in physiological adaptation to nutritional stress, focusing specifically on dietary protein deficiency during the juvenile period. Two critical developmental processes display pronounced sexual dimorphism under protein restriction: linear growth and reproductive maturation. Evidence from both preclinical and clinical studies indicates that juvenile protein restriction differentially affects these processes in males and females, highlighting the necessity of considering sex as a biological variable in experimental design and data interpretation. Shared endocrine signals, including Fibroblast Growth Factor 21, may contribute to these sex-specific adaptive responses. Further elucidating the nutritional, endocrine and metabolic mechanisms underlying sexually dimorphic outcomes of juvenile development is essential for enhancing the mechanistic value and translational relevance of preclinical and clinical research.