Diet and gene interaction.

Objective: To investigate the effect of chromium picolinate (CP) supplementation on body composition, resting metabolic rate (RMR), selected biochemical parameters and iron and zinc status in moderately obese women participating in a 12-week exercise program.

Methods: Forty-four women, 27 to 51 years of age, were randomly assigned to two groups based on their body mass index. Subjects received either 400 μg/day of chromium as a CP supplement or a placebo in double-blind fashion and participated in a supervised weight-training and walking program two days per week for 12 weeks. Body composition and RMR were measured at baseline, 6 and 12 weeks. Selected biochemical parameters and iron and zinc status were measured at baseline and 12 weeks.

Results: Body composition and RMR were not significantly changed by CP supplementation. No significant differences in fasting plasma glucose, serum insulin, plasma glucagon, serum C-peptide and serum lipid concentrations or in iron and zinc indices were found between the two groups over time. Serum total cholesterol concentration significantly decreased (p = 0.0016) over time for all subjects combined, probably as a result of the exercise training. Exercise training significantly reduced total iron binding capacity (TIBC) by 3% for all subjects combined (p = 0.0011).

Conclusions: Twelve weeks of 400 μg/day of chromium as a CP supplement did not significantly affect body composition, RMR, plasma glucose, serum insulin, plasma glucagon, serum C-peptide and serum lipid concentrations or iron and zinc indices in moderately obese women placed on an exercise program. The changes in serum total cholesterol levels and TIBC were a result of the exercise program.