title: Pricing and promotion effects on low-fat vending snack purchases: the CHIPS Study.
abstract: OBJECTIVE
  This study examined the effects of pricing and promotion strategies 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 (equal price, 10% reduction, 25% reduction, 50% reduction) and 3 promotional conditions (none, low-fat label, low-fat label plus promotional sign) were crossed in a Latin square design. Sales of low-fat vending snacks were measured continuously for the 12-month intervention.
  
  
  RESULTS
  Price reductions of 10%, 25%, and 50% on low-fat snacks were associated with significant increases in low-fat snack sales; percentages of low-fat snack sales increased by 9%, 39%, and 93%, respectively. Promotional signage was independently but weakly associated with increases in low-fat snack sales. Average profits per machine were not affected by the vending interventions.
  
  
  CONCLUSIONS
  Reducing relative prices on low-fat snacks was effective in promoting lower-fat snack purchases from vending machines in both adult and adolescent populations.
authors.affiliation: Division of Epidemiology, University of Minnesota, 1300 S Second St. Suite 300, Minneapolis, MN 55454-1015, USA. french@epi.umn.edu
authors.forename: S A
authors.initials: SA
authors.lastname: French
authors.forename: R W
authors.initials: RW
authors.lastname: Jeffery
authors.forename: M
authors.initials: M
authors.lastname: Story
authors.forename: K K
authors.initials: KK
authors.lastname: Breitlow
authors.forename: J S
authors.initials: JS
authors.lastname: Baxter
authors.forename: P
authors.initials: P
authors.lastname: Hannan
authors.forename: M P
authors.initials: MP
authors.lastname: Snyder
mesh_terms: D000293:Adolescent; D017195:Adolescent Nutritional Physiological Phenomena; D000328:Adult; D000329:Advertising; D000704:Analysis of Variance; D003362:Cost-Benefit Analysis; D004041:Dietary Fats / Q000008:administration & dosage*; D005509:Food Dispensers, Automatic / Q000191:economics* / Q000706:statistics & numerical data; D005518:Food Preferences; D006801:Humans; D008910:Minnesota; D016272:Occupational Health; D013334:Students
chemical_list: D004041:Dietary Fats