Diet quality is independently associated with weight status in children aged 9-10 years

Although energy imbalance is key to the development of childhood obesity, the association between different dietary components, reflected in diet quality scores, and children's weight status has not been extensively studied. The current study determined if diet quality, characterized according to 3 predefined scores, was associated with weight status in a population-based sample of 9- to 10-y-old British children, independently of factors previously associated with weight status. In a cross-sectional study of 1700 children (56% girls), data from 4-d food diaries were used to calculate 3 diet quality scores modified to be reflective of children's diets: the Diet Quality Index (DQI), Healthy Diet Indicator (HDI), and Mediterranean Diet Score (MDS). Physical activity was measured with 7-d accelerometery, and height, weight, waist, and bio-impedance were objectively measured and used to calculate weight status variables. After multiple adjustments, including physical activity and overall energy density, higher DQI and HDI scores were significantly associated with improved weight status. Comparing extreme quintiles of the scores revealed the DQI and HDI were associated with lower waist circumference (-3.0%, P = 0.005 and -2.5%, P = 0.033, respectively), and lower body fat (-5.1%, P = 0.023 and -4.9%, P = 0.026, respectively). The DQI was also associated with lower weight (-5.9%; P = 0.002) and BMI (-4.2%; P = 0.004). No significant associations were observed with the MDS. These findings suggest that diet quality is independently associated with children's weight status. Future work should consider if diet quality scores could be key components of interventions designed to reduce obesity in children.