The effect of weight cycling on blood lipids and blood pressure in the Multiple Risk Factor Intervention Trial Special Intervention Group

To assess whether weight cycling has adverse effects on blood lipids or blood pressure. Cohort study, six years of follow-up, comparing net change in blood lipids and blood pressure among weight cyclers and non-cyclers. Men (n = 4353), age 35-57 y, at high risk for heart disease because of smoking, high blood pressure, and elevated cholesterol concentration in the Multiple Risk Factor Intervention Trial (MRFIT)--a 22-site, multi-center collaborative primary prevention trial conducted in the US, 1973-1983. A weight cycle was defined as loss and regain of at least 5% of mean weight. Outcome measures were changes from baseline to year six in total serum cholesterol, high density lipoprotein cholesterol (HDL), the ratio of total cholesterol to HDL, and diastolic blood pressure. Analysis of covariance models were developed, with number of weight cycles as the predictor variable. The hypothesis was that men who weight cycled would experience less improvement in blood lipids and blood pressure than those who did not cycle. Adjustments were made for net weight change and other factors affecting each outcome. Men who weight cycled did not have the predicted smaller improvements in total cholesterol, HDL, the ratio of total cholesterol to HDL, or diastolic blood pressure, compared with noncyclers. An adverse effect of weight cycling on blood pressure or blood lipids was not found. The excess mortality previously reported among weight cyclers in this population can probably not be attributed to effects on these CVD risk factors.