Being overweight (BMI > 25) or obese (BMI > 30) has long been associated with an increased risk of heart disease. The lowest mortality from cardiovascular disease (CVD) and all other causes combined was found in both men and women with a BMI of 19.0 to 21.9. The association between BMI and heart disease weakens with age, but overall risk and absolute risk both increase with age. Data from the long-running Framingham Study found about a 30% increase in the risk of CVD for a 10% increase in body weight.

Being overweight increases the risk of developing Type 2 diabetes, hypertension, higher levels of triglycerides (TG) and apo B, an increased preponderance of small dense LDL particles (a.k.a. phenotype B), higher levels of fibrinogen and plasma activator inhibitor-I, a more exaggerated postprandial lipemia and a lower HDL. All of these factors have been shown to increase the risk of heart disease. Weight loss has been shown to reduce all of these risk factors. Weight loss has also been shown to slow the progression of atherosclerosis in obese people close to that of lean controls in a four-year study. In this study, the control obese subjects (who lost no weight) experienced a nearly 3-fold faster progression of their atherosclerosis as measured by changes in the intima-media thickness than those who lost weight and kept it off.It is not unusual for HDL to drop during active weight-loss. However, HDL usually recovers to higher than pre-diet levels if the lower body weight is maintained. Regular exercise should help raise HDL, lower TG and reduce insulin resistance. A goal of burning at least 300-400 kcal daily or 2000 kcal per week will not only promote weight loss but may improve many other heart disease risk factors seen in people with Syndrome X.Very impressive improvement in blood lipids were seen when weight loss resulted from the ad libitum consumption of a diet made up largely of unrefined high-CHO foods. On this diet, there was a dramatic reduction in TC (-33%), LDL (-41%), and TG (-21%), but no effect on HDL after 3 months and an average weight loss of 16 lbs. More importantly a very-low fat, near vegetarian diet has been shown to regress atherosclerosis and dramatically improve blood flow to the heart muscle. The best approach for overweight people at high risk for heart disease is a very-low-fat, high-fiber diet composed largely of unrefined high-CHO foods coupled with regular aerobic exercise. (Excerpted from 21st Century Heart)