Implementation of a 4-y, high-fiber, high-fruit-and-vegetable, low-fat dietary intervention: Results of dietary changes in the Polyp Prevention Trial

Elaine Lanza, Arthur Schatzkin, Cassandra Daston, Don Corle, Laurence Freedman, Rachel Ballard-Barbash, Bette Caan, Peter Lance, James Marshall, Frank Iber, Moshe Shike, Joel Weissfeld, Martha Slattery, Electra Paskett, Donna Mateski, Paul Albert

Research output: Contribution to journalArticlepeer-review

142 Scopus citations


Background: The Polyp Prevention Trial (PPT) was a multicenter randomized clinical trial designed to determine the effects of a high-fiber (4.30 g/MJ), high-fruit-and-vegetable (0.84 servings/MJ), low-fat (20% of energy from fat) diet on the recurrence of adenomatous polyps in the large bowel. Objective: Our goal was to determine whether the PPT intervention plan could effect change in 3 dietary goals and to examine the intervention's effect on the intake of other food groups and nutrients. Design: Participants with large-bowel adenomatous polyps diagnosed in the past 6 mo were randomly assigned to either the intervention (n = 1037) or the control (n = 1042) group and remained in the trial for 4 y. Three dietary assessment instruments were used to measure dietary change: food-frequency questionnaires (in 100% of the sample), 4-d food records (in a 20% random cohort), and 24-h dietary recalls (in a 10% random sample). Results: Intervention participants made and sustained significant changes in all PPT goals as measured by the dietary assessment instruments; the control participants' intakes remained essentially the same throughout the trial. The absolute differences between the intervention and control groups over the 4-y period were 9.7% of energy from fat (95% CI: 9.0%, 10.3%), 1.65 g dietary fiber/MJ (95% CI: 1.53, 1.74), and 0.27 servings of fruit and vegetables/MJ (95% CI: 0.25, 0.29). Intervention participants also reported significant changes in the intake of other nutrients and food groups. The intervention group also had significantly higher serum carotenoid concentrations and lower body weights than did the control group. Conclusion: Motivated, free-living individuals, given appropriate support, can make and sustain major dietary changes over a 4-y period.

Original languageEnglish (US)
Pages (from-to)387-401
Number of pages15
JournalAmerican Journal of Clinical Nutrition
Issue number3
StatePublished - 2001


  • Body weight
  • Clinical trial
  • Dietary change
  • Dietary fat intake
  • Dietary fiber intake
  • Dietary intervention
  • Fruit and vegetable intake
  • Nutrition intervention
  • Plasma cholesterol
  • Polyp Prevention Trial
  • Serum carotenoids

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics


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