The role of following the recommendations of Canada's Food Guide (CFG) and the Dietary Approaches to Stop Hypertension (DASH) diet on body composition in children is unknown. The present study assessed how conformity to the recommendations of these diets was associated with BMI, waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), waist girth (WG), hip girth (HG) and risk of overweight in peri-adolescents.

CFG and DASH indices were derived from responses to a food questionnaire, with a higher index representing greater conformity to CFG and DASH diet recommendations. Body composition was assessed by trained research assistants.

Schools within the Niagara region (Ontario, Canada).

Children (n 1570) aged 12·4 (sd 0·3) years.

After adjustment for age to peak height velocity and total physical activity, a higher CFG index was associated with lower WHtR (b = −0·001, 95 % CI −0·002, −0·0004), WHR (b = −0·001, 95 % CI −0·002, −0·001) and WG (b = −0·18, 95 % CI −0·30, −0·07) in girls. No associations were observed in boys. In contrast, a higher DASH index was associated with decreased body composition measures in both genders. Specifically, the DASH index was negatively associated with BMI (girls: b = −0·07, 95 % CI −0·10, −0·04; boys: b = −0·05, 95 % CI −0·08, −0·02), WHtR (girls: b = −0·001, 95 % CI −0·002, −0·001; boys: b = −0·001, 95 % CI −0·002, −0·0004), WHR (girls: b = −0·001, 95 % CI −0·002, −0·001; boys: b = −0·001, 95 % CI −0·001, −0·00004), WG (girls: b = −0·24, 95 % CI −0·31, −0·16; boys: b = −0·15, 95 % CI −0·24, −0·07) and HG (girls: b = −0·15, 95 % CI −0·23, −0·07; boys: b = −0·12, 95 % CI −0·19, −0·04). A higher DASH index was also associated with lower odds of overweight in girls (OR = 0·70, 95 % CI 0·56, 0·87) and boys (OR = 0·76, 95 % CI 0·62, 0·93).

The DASH diet may prevent overweight in peri-adolescents.