Food intake patterns and body mass index in observational studies

Objective: To review studies of patterns of food intake, as assessed by die t index, factor analysis or cluster analysis, and their associations with b ody mass index or obesity (BMI/Ob). Design: Systematic literature review MEDLINE search with crosscheck of refe rences. Studies: Thirty observational studies relating food intake patterns to anth ropometric information were identified and reviewed. Food intake patterns w ere defined using a diet index, factor or cluster analysis in 12, nine and nine studies, respectively. Measures of body mass were made concurrently wi th the diet assessment in all studies, and only in a few cases were the pri mary outcomes related to BMI/Ob. Results: The food intake patterns identified could, in most factor or clust er analysis studies, be categorised as: (a) meat, fatty, sweet or energy de nse foods; (b) vegetables, fruit, whole grain and low-fat foods; or (c) by high alcohol consumption. The diet indexes were designed to capture a high diversity and/or food combinations matching the recommendations. The relati onships with BMI/Ob were inconsistent-ten studies found that intake pattern s, which we categorised as fatty, sweet or energy dense were positively ass ociated with BMI/Ob, while similar patterns in four other studies were nega tively associated with BMI. The significant associations between diet index score and BMI/Ob were consistently negative, while the associations betwee n factor scores or cluster membership and BMI/Ob were less clear in terms o f food intake pattern. Men and women had similar food intake patterns, but food intake patterns were less often positively associated with BMI/Ob in w omen. In 11 studies, there were no significant associations between food in take pattern and BMI/Ob. Conclusion: This review showed that no consistent associations could be ide ntified between BMI or Ob and food intake patterns, derived from diet index , factor analysis or cluster analysis. However, the heterogeneity of food i ntake patterns identified by such analyses and the lack of gold standards f or the application of these techniques hampers consistent analysis of a rel ation between food intake patterns and health.