PURPOSE: We recently showed that provision of Nordic school meals rich in fish, vegetables and potatoes and with reduced intakes of fat improved blood pressure, insulin resistance assessed by the homeostatic model (HOMA-IR), and plasma triacylglycerol despite increasing waist circumference in Danish 8-11-year-olds. This study explored whether intake or biomarkers of key dietary components in the schools meals were associated with these metabolic syndrome (MetS) markers during the 6-month intervention.

METHODS: Data from 7-day dietary records and measurements of whole-blood docosahexaenoic acid (DHA, 22:6n-3), blood pressure, fasting blood MetS markers, waist circumference and android/total fat mass assessed by dual-energy X-ray absorptiometry collected at baseline, 3 and 6 months from 523 children were analyzed in linear mixed-effects models adjusted for puberty, growth and fasting.

RESULTS: After adjustment for multiple testing, whole-blood DHA was negatively associated with HOMA-IR (P < 0.001) and triacylglycerol (P < 0.0001). Potato intake was positively associated with waist circumference (P < 0.01), but not with android/total fat mass (P = 0.94). Intakes of whole-grain as well as dietary fiber, protein and fat were not associated with any of the MetS markers.

CONCLUSIONS: DHA in whole-blood, an indicator of DHA and fish intake, seemed to be the main diet-related predictor of the beneficial effects of the school meals on MetS markers. Increased potato intake was associated with increased waist circumference, but this may not only be due to an increase in abdominal fat, as no association was seen with fat distribution.