Dr. Mark Hyman explains why low-fat diets fail for weight loss. Genes and dietary fat matter less than insulin response. Research by Dr. David Ludwig shows a low glycemic load, whole foods diet works better for managing weight.
Obesity genes account for only 5% of all weight problems. Hi, this is Dr. Mark Hyman. Welcome back to my blog. So what about the other 95% of weight problems? Why are we seeing such an epidemic of obesity in America today? It's the single most important public health issue facing us. So if our genes don't account for obesity, is it our high fat diet? Well, as we all learned in medical school, fat makes you fat. And fat contains nine calories per gram, so eating more fat will get you more calories and you'll gain more weight. Seems obvious, right? Wrong. In fact, pioneering research by David Ludwig from Harvard Medical Schools, who I've written about before in a previous blog regarding his book called ending the food fight, which is actually going to be released in paperback on April 17th, has done groundbreaking research that shows us the real reason that low fat diets do not work and discovered the true cause of obesity for most Americans. He published two recent studies, one in the Journal of the American Medical Association on May 6, 2007 and one in the American Journal of Clinical Nutrition in 2008. Now he correctly pointed out The careful review of all the studies on dietary fat and body fat, such as those done by Walter Willett of Harvard School of Public Health, have shown that dietary fat is not a major determinant of body fat. In fact, other research studies like the Women's Health Initiative, which is the largest clinical trial of diet and body weight, showed 50,000 women on low-fat diets had no significant weight loss. Another study looked at 12 months with people on four different diets including no dramatic, including Ornish and Atkins and so forth, showed no dramatic differences between the groups of very low fat, low carb and very low carb diets. And the question then becomes, why are we seeing no significant effect from these various diets? Well, the main reason Dr. Ludwig suggests is that we're looking in the wrong place for the answers. The future of treating obesity and weight is personalizing our approach. That's what I wrote about in my book Ultra Metabolism called Nutra Genomics. This is the science of how we use food to influence our genes and personalize our approach to health. Over the last 15 years, I have tested almost every one of my patients using a test that most doctors never use. In fact, it is even harder to find in the research except in this pioneering work by Dr. David Ludwig. This test is cheap, it's easy to do and it's probably the most important test for determining your overall health, the causes for obesity, your risk of diabetes, heart disease, cancer, Alzheimer's and premature aging. And unfortunately, it's something your healthcare provider does not do, does not know how to interpret and often thinks is useless. Thankfully, this new research by Dr. David Ludwig, author of Ending the Food Fight and professor at Harvard Medical School, brings this critical method of diagnosing the cause of obesity and disease to the forefront. In his two recent studies, he found that the main factor that determines changes in body weight and waist circumference, also known as belly fat, is how your own system, your own body, responds to any type of sugar, carbohydrate, or glucose load. The most important thing to measure is not your blood sugar, it's not your cholesterol, it's your insulin level. But you have to check it after drinking a sugary drink containing 75 grams of glucose. This is a test I've been doing for 15 years and it's shown me more about my patients than any other test. It helps me personalize and customize a nutritional approach for them. This is now being borne out by this research by Dr. David Ludwig and his colleagues. In one study, Dr. Ludwig and his colleagues studied 276 individuals in a Quebec family study and followed them for six years. They performed a glucose tolerance test at the beginning of the study and looked at insulin concentrations 30 minutes after they took a sugary drink, which gave them a rough estimate of whether they were high or low insulin secretors, whether they produced too much or too little insulin. Over the six years, they looked at the body weight and the waist circumference or belly fat. They found that those who were the highest insulin secretors, who had the most insulin, had the biggest change in weight, they gained the most weight, and belly fat compared to the low insulin secretors. They found that in fact those who ate low fat diets and were high insulin secretors actually did worse. So why does this happen? Well it makes perfect sense because insulin does two things. One, it stimulates hunger, so it makes you eat more, and two, it's a fat storage hormone, which makes you store belly fat. So when you spike your insulin right after a carbohydrate meal, your blood sugar plummets, creating a little while later, low blood sugar. And that makes a life-threatening emergency, which makes you very hungry. That's why you crave more carbs and more sugar. and why you eat more the whole day. He also found that in patients who ate the low glycemic load diet, which lowers the blood sugar and keeps the insulin levels low, they had much higher levels of the good cholesterol or HDL and much lower levels of triglycerides. So it appears that the best way to address your cholesterol is not necessarily eating a low fat diet, but eating a low glycemic load diet which keeps your blood sugar even. I recommend becoming familiar with Dr. David Ludwig's work by encouraging you to go look at his research on PubMed, which is the National Library of Medicine's database, because you'll learn more about his pioneering and exciting work. It's really tremendous. I also encourage you to read his book, Ending the Food Fight: Guide youe Child to a Healthy Weight in a Fast Food, Fake Food World. It's the first and only roadmap for dealing with our exploding childhood obesity epidemic. In addition, I encourage you to ask your physician to do a glucose tolerance test and measure insulin along with blood sugar at 30 minutes, 1 hour and 2 hours to get the best picture of your insulin profile. If you're a high insulin secretor and your insulin goes over 30 at half hour, 1 hour or 2 hours, you produce too much insulin and need to be sure you're staying on a low glycemic load Whole Foods unprocessed diet which are described in Ultra Metabolism. The bottom line, if you want to fit into your jeans, you have to fit into your jeans and eat the way your body was designed, which is a whole foods unprocessed low glycemic load, phytonutrient rich diet.
