March 13, 2006 — High calcium and dairy intake do not reduce long-term weight gain in men, according to an analysis of data from the Health Professional Follow-Up Study reported in the March issue of the American Journal of Clinical Nutrition.

"A higher calcium intake could potentially have an antiobesity effect, write Swapnil N. Rajpathak, from the Albert Einstein College of Medicine in Bronx, NY, and colleagues." However, the role of calcium in the maintenance of body weight remains controversial, and only a few studies have examined the relation between calcium intake and long-term weight change."

The Health Professionals Follow-up Study is a prospective cohort study of men aged 40 to 75 years in 1986. Participants reported their body weight in 1986 and in 1998, and they updated information regarding their lifestyle factors and diet using self-administered questionnaires. The main endpoint in this analysis was weight change for the 12 years of the study, as a function of baseline calcium and dairy intake (n = 23 504) and change in calcium and dairy intake (n = 19 615).

Multivariate analysis with adjustment for potential confounders revealed that baseline or change in total, dietary, dairy, or supplemental calcium intake was not significantly associated with weight change. The men with the largest increase in total dairy intake gained slightly more weight than did the men who decreased intake the most, primarily because of an increase in high-fat dairy intake (3.14 vs 2.57 kg; P for trend = .001). Low-fat dairy intake was not significantly associated with weight change.

"Our data do not support the hypothesis that an increase in calcium intake or dairy consumption is associated with lower long-term weight gain in men," the authors write. "The modest positive association between dairy intake and weight gain is probably due to components of dairy other than calcium."

Study limitations include observational design, inability to determine whether changes in body weight were due to changes in either fat mass or lean mass, measurement error related to dietary assessment tending to bias the results toward the null, and possible residual confounding.

"Whether calcium supplementation or increased dairy intake is beneficial in preventing weight gain needs to be further studied in long-term randomized trials," the authors conclude.

The National Institutes of Health supported this study. The authors have disclosed no relevant financial relationships.

Am J Clin Nutr. 2006;83:559-566