Obesity (overweight) has remained a public health problem, on account of its attendant complications viz diabetes, hypertension and atherosclerosis. To arrest the significant decrease in life expectancy affiliated upon the older age group by obesity, dietary induced weight loss has been sought. This study assessed the effect of dietary theobromine (theobromine rich cocoa powder diets) on weight changes and lipid profile of Wistar rats. The inclusion of 3% to 15% cocoa powder in the diet corresponding to an estimated 56 +/- 15.15 to 265 +/- 0.13mg of theobromine intake for 28 days, induced a significant (P < 0.05) rapid weight loss in the rats exposed to the test diet relative to the controls, the weight loss becoming significant after about a week of exposure. Lipid profile analysis on day 28(th) showed a significant (P < 0.05) decrease in total serum cholesterol, triglycerides and VLDL cholesterol but HDL cholesterol was significantly (P < 0.05) elevated in treatments relative to controls. The biochemical role of theobromine in the observed weight loss is discussed in respect to lipid metabolism and dietary control of obesity.