Adequate sleep quality is crucial for overall health, affecting physiological and psychological well-being. This systematic review examined the relationship between sleep quality, Body Mass Index (BMI), dietary habits, and socioeconomic factors among young adults (18–35 years). A total of 39 studies published since 2019 were reviewed. A meta-analysis of 20 studies revealed a significant positive association between poor sleep quality and higher BMI, with high heterogeneity ( I 2 = 88.22%). Evidence indicates a bidirectional relationship where short sleep duration contributes to weight gain, while higher BMI reduces sleep quality and duration. Healthy diets, such as the Mediterranean diet and calcium-rich products, are associated with improved sleep quality, while socioeconomic factors, including financial stress, influence these relationships and highlight health inequalities. However, most studies did not explore causal relationships, directionality, between these variables and changes in sleep quality. Future research should interpret these mechanisms and develop strategies to improve sleep hygiene and overall health.
Ahn et al. (2025) studied this question.