Eighteen studies were included in the review: 11 randomised controlled trials; four non-randomised non-controlled trials; two non-randomised controlled trials; and one cross-sectional study). Where stated, sample sizes ranged from 135 to 5,106 children.
Nutrition guidelines (nine studies): Three of four studies found that intervention schools had a significant reduction in total and saturated fat on school menus; one study found no difference in total and saturated fat. Four studies showed that intervention guidelines led to increased fruit and vegetable availability. Three studies reported significant decreases of total fat and saturated fat intake from use of guidelines and two studies reported increases in fruit and vegetable intake. The one study that evaluated impact on body mass index found no difference between groups after one year of follow-up.
Price interventions (eight studies): Two studies reported significant increases in low fat snacks and fruit and vegetable sales following price reductions. Four studies that offered fruit and vegetables for free (or by subsidised subscription) showed statistically significant increases in fruit consumption either during or after the programmes.
Regulation of food and drink availability (two studies): Both studies used a restrictive nutrition policy to limit access to unhealthy foods and both suggested the policy was associated with significant, but limited, reductions in unhealthy food sales.