Syndrome X

Avoid Syndrome XWe examined the bogus claims made in Sugar Busters and Enter the Zone in a previous article. These books say that high-carbohydrate (CHO) diets, particularly those with a high glycemic index (GI), promote a host of metabolic problems. Some researchers call these problems Syndrome X. Now we will take a closer look at some of the research and why the design of these studies limits their clinical relevance.What is Syndrome X?Syndrome X is a combination of metabolic problems that may include: elevated triglycerides, decreased HDL or ?good? cholesterol, insulin resistance, high blood pressure and hyperinsulinemia. Most of the people who have Syndrome X have an apple shape with a disproportionate amount of fat around their waist. Many have or will develop non-insulin dependent diabetes mellitus.What causes Syndrome X?The results of many studies have shown that high-carbohydrate diets appear to aggravate Syndrome X by causing higher blood sugar and insulin levels and adverse effects on blood lipids when compared to diets higher in unsaturated fat. But do the results of these studies apply to the real world?One criticism of these studies is that they required the subjects to consume the same amount of calories on both the high-fat and the high-CHO diets. In several such studies the researchers stated that they had difficulty getting people to eat as many calories on a high-CHO diet as they ate willingly on the higher fat diet. In real life, people generally eat until they are full. So studies that require people to eat a set amount of calories do not necessarily reflect what happens in the long run because few people can adhere to diets which require them to eat more (or less) food than appetite demands. One of the most important metabolic benefits of a high-CHO diet is feeling full on fewer calories than needed on a higher fat diet.In studies where people (rather than researchers) determined their food intake, the high-CHO diet actually reduced cardiovascular disease risk factors compared to diets with more monounsaturated fat. So it appears that it is the consumption of excess calories, rather than the ratio of CHO to fat, that is primarily responsible for promoting Syndrome X and increasing the risk of cardiovascular disease and diabetes.When researchers varied the fat content of foods subtly, people increased their calorie intake and gained weight as dietary fat increased. However, high fat diets do not invariably lead to increased calorie intake compared to high-CHO diets if the calorie-density of these two diets is the same.Why is calorie density important?Calorie density refers to how concentrated the calories are in a food. For example, carrots have a lower calorie density compared to potato chips. A pound of carrots contains around 195 calories while a pound of potato chips contains 2431 calories. Fresh fruits, vegetables, many whole grain foods, non-fat dairy products and very lean animal protein foods have a very low to moderate calorie density or less than 500 calories per pound.The addition of fat to foods invariably increases their calorie density; most naturally occurring high-fat foods have a high calorie density so it is very difficult to consume a high-fat, low calorie dense diet. It is precisely because diets higher in fat are almost always more calorie dense that they are also more likely to lead to excessive calorie intake, weight gain and metabolic problems, including Syndrome X when compared to diets higher in CHO.A study reported in the American Journal of Clinical Nutrition compared a low-calorie dense diet consisting primarily of minimally processed plant foods that are high in fiber and low in fat to a typical high-fat low-fiber American diet. Researchers found that the calorie intake was dramatically lower on the low calorie dense diet (3000 versus 1570 calories a day).So how do I avoid Syndrome X, Diabetes and Cardiovascular Disease?The most important thing you can do to avoid Syndrome X is to increase your consumption of naturally low calorie-dense foods. Go for a diet high in minimally processed whole grain foods like pasta, hot cereals, corn and brown rice. Eat generous amounts of fruits, vegetables and starchy foods like potatoes, beans, lentils and peas. Stay with modest amounts of nonfat dairy products and a little seafood or very lean poultry or meat. Keep your fat intake low. But avoid or minimize foods high in refined carbohydrates such as fat free cookies, cakes and chips. This approach appears to be the best for preventing and treating Syndrome X as well as preventing heart disease, obesity and diabetes.Increase your activity level. If you haven?t been active in a while, see your doctor. Start slow and be consistent. The ideal would be to walk or jog 3-4 miles a day, 6-7 days a week. A more active lifestyle aids weight loss and diminishes the metabolic problems like those associated with Syndrome X.By Dr. Jay Kenney, PhD, RD, FACN.Dr. Jay Kenney is the Nutrition Research Specialist for the Pritikin Longevity Centers. He is on the Board of Directors for the National Council Against Health Fraud. Hie is Board Certified as a specialist in Human Nutrition Sciences by the American Board of Nutrition.If you would like to see his full text article with over 20 scientific references and complete a questionnaire for one CPE hour for RDs, visit our web site at www.foodandhealth.com or see the insert in this issue.