Abstract
OBJECTIVE: To investigate how mealtime setting, mealtime interaction and bedroom screens are associated with different trajectories of child overweight and obesity, using a population sample. METHODS: Growth mixture modelling used data from children in the Growing Up in Scotland Study born in 2004/5 (boys n = 2085, girls n = 1991) to identify trajectories of overweight or obesity across four time points, from 46 to 122 months. Using data from children present at all sweeps, and combining sexes (n = 2810), mutually adjusted associations between primary exposures (mealtime setting, mealtime interaction and bedroom screens) and trajectory class were explored in multinomial models; controlling for early life factors, household organisation and routines, and children's diet patterns, overall screen use, physical activity and sleep. RESULTS: Five trajectories were identified in both sexes: Low Risk (68% of sample), Decreasing Overweight (9%), Increasing Overweight (12%), High/Stable Overweight (6%) and High/Increasing Obesity (5%). Compared with the Low Risk trajectory, High/Increasing Obesity and High/Stable Overweight trajectories were characterised by early increases in bedroom screen access (respective relative risk ratios (RRR) and 95% confidence intervals: 2.55 [1.30-5.00]; 1.62 [1.01-2.57]). An informal meal setting (involving mealtime screen use, not eating in a dining area and not sitting at a table) characterised the High/Increasing Obesity and Increasing Overweight trajectories (respective RRRs compared with Low Risk trajectory: 3.67 [1.99-6.77]; 1.75 [1.17-2.62]). Positive mealtime interaction was associated with membership of the Increasing Overweight trajectory (RRR 1.64 [1.13-2.36]). CONCLUSION: Bedroom screen access and informal mealtime environments were associated with higher-risk overweight and obesity trajectories in a representative sample of Scottish children, after adjusting for a wide range of confounders. Findings may challenge the notion that positive mealtime interaction is protective. Promoting mealtimes in a screen-free dining area and removing screens from bedrooms may help combat childhood obesity.