# Obesogenic behaviors during structured periods among children and adolescents with intellectual and developmental disabilities: a systematic review and meta-analysis

## TL;DR

This study reviews how structured periods affect obesity-related behaviors in children and adolescents with intellectual and developmental disabilities, finding that more structure improves physical activity and diet.

## Contribution

The study extends the Structured Days Hypothesis to children with intellectual and developmental disabilities, revealing specific impacts on physical activity and diet.

## Key findings

- Periods of greater structure are linked to better physical activity outcomes in children with IDD.
- Diet improves during structured periods, but evidence is limited.
- Sleep and sedentary behaviors do not align with the Structured Days Hypothesis.

## Abstract

Children and adolescents with intellectual and developmental disabilities (IDD) are at greater risk for obesity and poor obesogenic behaviors (e.g., physical activity, screen time, diet, sleep) than their typically developing counterparts. The Structured Days Hypothesis (SDH) suggests that in typically developing children and adolescents, obesogenic behaviors worsen during periods of reduced structure (e.g., weekend or summer vacation). However, children and adolescents with IDD have unique factors that may alter how structure (i.e., pre-planned, segmented, adult supervised, out-of-home programs) influences obesogenic behaviors. Therefore, the objective of this systematic review and meta-analysis is to examine obesogenic behaviors during periods of more and less structure among children and adolescents with IDD.

A comprehensive search of PubMed, PsycINFO, Embase, and Web of Science was performed through the end of 2024 based on the PICO framework. Studies were eligible if they included youth with IDD and measured obesogenic behaviors across contexts with differing degrees of structure. Two reviewers independently completed the screening process, extracted all relevant information, and evaluated methodological quality using the NHLBI tool. Results were synthesized using fixed- and random-effects meta-analyses and visually represented with forest plots.

A total of 4,236 papers were screened with 323 full-text articles retrieved. After screening, 33 total studies were identified (physical activity = 23, sedentary behaviors = 12, sleep = 11, diet = 1). Meta-analyses indicated that the standardized mean difference of physical activity (Random = 0.27, [95%CI: 0.13–0.40], p < 0.00), and diet (0.16, [95%CI: 0.03–0.29], p = 0.02) aligned with the SDH while sleep (Random = -0.01, [95%CI: -0.16-0.14], p = 0.88), sedentary and screen time (Random = -0.01, [95%CI: -0.38-0.36], p = 0.95) did not align.

Periods of greater structure were associated with more favorable physical activity and diet outcomes among children and adolescents with IDD, although evidence for dietary behaviors was limited. Findings support the relevance of the SDH in this population while highlighting substantial gaps in the literature, including small study numbers and methodological heterogeneity. Future research using rigorous, longitudinal designs is needed to better understand the relationship between structure and obesogenic behaviors among children and adolescents with IDD.

The online version contains supplementary material available at 10.1186/s12966-026-01881-5.