The role of lifestyle factors in type 2 diabetes in children and adolescents: a systematic review.

BACKGROUND: Rates of type 2 diabetes in children and young people are rising worldwide; however, the role of lifestyle factors in the management of type 2 diabetes are less clear for this age group. The purpose of this systematic review was to examine associations between lifestyle factors (physical activity, sedentary behaviour, sleep, diet/nutrition), and effects of lifestyle modification interventions, on (1) primary type 2 diabetes indicators (i.e., HbA1c) and (2) secondary (i.e., insulin-related variables; anthropometry; cholesterol; triglycerides; cardiac, liver and kidney health/function; blood pressure; mental health and quality of life; fitness and strength) indicators in children and adolescents with type 2 diabetes. METHODS: Seven databases (CINAHL, Cochrane, Embase, PsycInfo, PubMed, Scopus) were searched from inception to February 2025 for primary peer-reviewed articles, written in English. Articles must have evaluated one-or-more lifestyle factors and primary or secondary diabetes indicators in children and adolescents (< 18 years) with type 2 diabetes. Both observational and experimental studies were included. Study quality was assessed using the National Collaborating Centre for Methods and Tools Assessment Tool for Quantitative Studies. Data synthesis was guided by the Cochrane Synthesis Without Meta-analysis guidelines. RESULTS: Twenty six articles were eligible (63% were conducted in the USA); 15 experimental, targeting combined diet and physical activity (n = 9, duration 16wks-12mo), physical activity alone (n = 3, duration 12-16wks), and diet alone (n = 3, duration 9-34wks). The remaining studies were observational and evaluated combined diet and physical activity (n = 2), physical activity (n = 4), sedentary behaviour (n = 1), sleep (n = 1), and diet/nutrition (n = 5). Increased engagement in a combination of physical activity and healthy diet, and improved sleep quality, were associated with lower HbA1c. An unclear or no relationship existed between physical activity or diet/nutrition alone with HbA1c, and secondary indicators. Evidence was provided for the positive impact of diet on HbA1c, and for physical activity on anthropometric variables. CONCLUSIONS: Compared to the body of literature available in adults, evidence for the role of lifestyle factors in children and young people is limited. Lifestyle factors show promise for managing disease burden in children and adolescents, but outcomes remain unclear as existing research is heterogeneous.