Effectiveness of Pulse-Based Foods Combined With Exercise for Improving Components of the Metabolic Syndrome

The investigators specific objective is to determine the effectiveness of a pulse-based diet combined with an exercise training program for reducing the risk of metabolic syndrome in older adults. The metabolic syndrome is a cluster of risk factors that predispose one to the development of diabetes and cardiovascular disease. These risk factors include increased abdominal obesity, high blood triglyceride levels, low blood high-density lipoproteins, high blood pressure, high blood glucose and insulin levels, and increased inflammation. The investigators hypothesize that a pulse-based diet combined with exercise training will be very effective for reducing the risks of the metabolic syndrome because each intervention acts on different components of the metabolic syndrome.

The design will involve a randomized single-blind cross-over for the pulse-based diet, and a single blind randomized parallel group assignment for the exercise-based intervention. 100 subjects will be randomized to receive the pulse-based diet or their regular diet for 2 months and then cross-over to receive the opposite diet for 2 months, separated by a one-month "wash out". Subjects will be further randomized to exercise or "exercise placebo" groups for the duration of the trial (i.e. 5 months). The exercise intervention will involve aerobic training as this is most effective for reducing metabolic syndrome risk.

Dependent variables will be measured at 4 time points: baseline, after the first 2-month diet, before the second 2-month diet (i.e. after the washout) and at the end of the second 2-month diet. These variables will include: Serum triglycerides, high density lipoproteins, C-reactive protein (as an inflammatory marker), glucose, and insulin, trunk body fat, and blood pressure. A composite metabolic syndrome score will be determined by converting each of these variables into Z-scores and determining the mean of these Z-scores. Secondary variables will include other serum lipids, including low density lipoproteins and total cholesterol.