Cardiovascular disease is a complex multifactorial disease which is still not completely understood. Dating back to the 1950’s it was believed that dietary lipids including cholesterol and saturated fats were the main cause of cardiovascular disease. However, this cholesterol theory of cardiovascular disease has been almost completely discredited now. More recent evidence suggests that cardiovascular disease results from the development of metabolic dysfunction brought about by a poor quality diet containing refined foods and metabolic poisons that have detrimental effects on central lipoprotein and energy metabolism, while at the same time allowing dysfunction in the endothelial lining of the vasculature. A number of biochemical changes occur with this metabolic dysfunction, and these can be measured clinically to assess the risk of cardiovascular disease in an individual. In particular, the level of insulin resistance, blood pressure, and changes in lipoprotein levels can be used to assess an individual’s risk.
However, these tests are invasive and difficult to perform outside of a clinical setting. Even within a clinical setting the tests are known to be unreliable for a number of reasons including a lack of knowledge by the tester in interpreting the results, normal circadian changes and natural variation in the parameters. Because of these problems a number of anthropometric tests have been devised to assess the risk of cardiovascular disease in an individual, the most commonly used of these being the body mass index (BMI). The body mass index is a measure of the weight of a person divided by the height of the person squared (kg/m2). This is useful because it gives an indication of how fat someone is, and fatness is generally associated with cardiovascular disease. However, it is abdominal obesity and not total fatness that is most closely associated with cardiovascular disease, because abdominal obesity characterises the development of the metabolic dysfunction (metabolic syndrome) that affects energy metabolism and gives rise to the accumulation of visceral fat.
Because it is not total body fat that determines cardiovascular disease risk, but the abdominal fat levels, the waist to hip ratio is considered a better predictor of cardiovascular risk when compared to the body mass index. The waist to hip ratio measures the ratio between the hips and the waist of an individual and is therefore an accurate measure of the degree of abdominal fat and this in turn is a better predictor of the presence of the metabolic syndrome. However, even just the circumference of the waist is also often used. Generally it is accepted that the waist to hip ratio or waist circumference are the prefered measure of cardiovascular risk, although in a clinical setting the BMI is prefered as it is less invasive and easier to perform. The main problem with the BMI is that it does not make allowances for those with large amounts of skeletal muscle, such as athletes, or those who are fat, but hold the fat subcutaneously. Such individuals may appear to have a higher risk of cardiovascular disease using the body mass index, but not using the waist measurements.
Studies have compared the reliability of the body mass index to the waist circumference and there is considerable overlap between people with an abnormal BMI and waist circumference (around 80 %)1. In men and women both BMI and waist circumference correlate with systolic blood pressure, fasting plasma triglycerides (very low density lipoprotein), and fasting plasma glucose levels, and inversely correlate with high density lipoprotein. The reason that BMI is able to predict cardiovascular disease despite is being inaccurate in athletes and those with subcutaneous fat is because the fact is that most people in the West are fat and have metabolic syndrome. This places the athletes and those with subcutaneous fat in such a small category that they become insignificant in the grand scheme of things. An even easier way to determine the risk of cardiovascular disease is to ask people what they eat. Assuming they give accurate details, the consumption of Western foods within a typical Western diet can accurately predict cardiovascular risk non-invasively.
Dr Robert Barrington’s Nutritional Recommendation: A high BMI predicts overall obesity but a high waist to hip ratio and waist circumference predict abdominal obesity. The latter two are clearly therefore better predictors of the presence of the metabolic syndrome and therefore of cardiovascular risk. However, the presence of refined white flour, trans fats, sugar, and high intakes of processed and refined foods is the best predictor of cardiovascular disease, because it is the actual cause.
RdB
