Pricing and promotion effects on low-fat vending snack purchases: The CHIPS study

Objectives. This study examined the effects of pricing and promotion strate gies on purchases of low-fat snacks from vending machines. Methods. Low-fat snacks were added to 55 vending machines in a convenience sample of 12 secondary schools and 12 worksites.: Four pricing levels (equa l price, 10% reduction, 25% reduction, 50% reduction) and 3 promotional con ditions (none, low-fat label, low-fat label plus promotional sign) were cro ssed in a Latin square design. Sales of low-fat vending snacks were measure d continuously for the 12-month intervention. Results. Price reductions of 10%, 25%, and 50% on low-fat snacks were assoc iated with significant increases in low-fat snack sales; percentages of low -fat snack sales increased by 9%, 39%, and 93%, respectively. Promotional s ign-age Was independently but weakly associated:with increases in low-fat s nack sales. Average profits per machine were not affected by the vending in terventions. Conclusions. Reducing relative prices on low-fat snacks was effective in pr omoting lower-fat snack purchases from vending machines in both adult and a dolescent populations.