Loneliness, problematic digital media use, and nutritional-metabolic vulnerability in adolescents from single-parent households: an integrative review of eating- and sleep-related pathways.

Adolescents from single-parent households may experience household time, economic, supervisory, and routine-related constraints that are relevant to psychosocial well-being, digital media use, eating behavior, sleep, and metabolic health. The objective of this integrative review was to synthesize evidence on the associations of loneliness and problematic digital media use with eating- and sleep-related behaviors in adolescents and to examine how single-parent household characteristics may influence these relationships. The review applies a contextual-behavioral vulnerability model in which household characteristics are treated as contextual modifiers; loneliness and problematic digital media use as the principal psychosocial and behavioral exposures; emotional eating, irregular meal timing, distracted eating, sleep disruption, circadian delay, and sedentary behavior as candidate intermediate processes; and diet quality, adiposity, and metabolic vulnerability as distal outcomes. Eligible evidence included peer-reviewed empirical studies, systematic reviews, and meta-analyses focused primarily on adolescents and examining at least one relevant association among family structure, loneliness, digital media use, eating behavior, sleep, energy balance, adiposity, or metabolic indicators. Studies explicitly analyzing single-parent households were treated as direct evidence, whereas broader adolescent or mechanistic studies were included when direct evidence was limited and were interpreted as indirect evidence. Direct single-parent evidence was concentrated mainly on family meals, screen-related routines, physical activity, and weight-related outcomes. Broader adolescent evidence associated loneliness with emotional eating and problematic digital media use with breakfast skipping, irregular meals, distracted eating, poorer diet quality, and sleep disruption. Evidence linking these behavioral patterns to adiposity, insulin sensitivity, circadian regulation, stress responsivity, and appetite-related signaling remained predominantly indirect and observational. Longitudinal, objectively measured, and biomarker-informed studies are needed to test these relationships directly in adolescents from single-parent households.