In this series of interviews I've conducted with extraordinary nutritional researchers and medical doctors, I've sought to understand the link between diet and health. The common refrain is resoundingly clear in that a plant-based diet is both preventive and healing, whereas a diet high in animal protein is destructive to our health. And now it's become abundantly evident that a high protein diet is not only making us sick, but it also makes us fat.
There is no one who has more peer reviewed research on the subject of weight loss and overall health than Dean Ornish, M.D. He has sparked a revolution in cardiology with his studies which show that heart disease can be reversed through comprehensive lifestyle changes. His current research is showing that those very changes also affect gene expression -- that you can turn on or turn off genes that affect cancer, heart disease and longevity. He is the founder and President of the non-profit Preventive Medicine Research Institute and is a Clinical Professor of Medicine at the University of California, San Francisco. Here's what he says about losing weight the healthy way, and keeping it off.
KF: It's widely believed that people lose weight fastest on a high protein diet. True?
DO: Initially, they may lose more weight because they are losing water weight. But by the end the year, the weight usually returns. In general, slower weight loss by eating more healthfully is more sustainable. Slow but steady wins the race.
KF: Why do some people have such a hard time losing weight and keeping it off?
DO: It's not enough to focus only on what we eat and other behaviors; we need to work at a deeper level. The real epidemic in our country is not only obesity but also depression, isolation, and loneliness. As one patient told me, "When I feel lonely and depressed, I eat a lot of fat. It fills the void. Fat coats my nerves and numbs the pain." People often overeat when they're feeling stressed, lonely, and depressed --"comfort foods."
Everyone knows that diet and exercise play a role in how much we weigh, but many are surprised to learn what a powerful role emotional stress has in causing us to gain weight and how stress management techniques can help us to lose it and keep it off.
Chronic emotional stress causes us to gain weight in several important ways:
• Many people overeat to cope with feeling stressed, and they often tend to eat foods that are high in fat, salt and sugar as well.
• Chronic emotional stress stimulates your brain to release hormones that cause you to gain weight, especially around your belly where it's most harmful and least attractive. Chronic stress also causes stimulation of hormones such as cytokines that promote inflammation. Also, obesity itself causes a low-grade inflammation which, in turn, tends to promote more obesity in a vicious cycle.
• Since chronic emotional stress promotes weight gain, stress management techniques may play a powerful role in helping you to lose weight and keep it off. The psychosocial, emotional and spiritual issues are as important to address if you want to lose weight and keep it off as the nutrition and exercise ones.
Most Americans eat too many refined carbohydrates. When they go on a typical high-protein diet, they reduce their intake of all carbohydrates, which for most Americans means they primarily reduce their intake of simple carbohydrates. This helps them to lose weight.
Whenever I debated Dr. Atkins before he died, he was usually described as the "low carb" doctor and I was the "low fat" doctor. But that was never accurate. I have always advocated that an optimal diet is lower in total fat, very low in "bad fats" (saturated fat, hydrogenated fats, and trans fatty acids), high in "good carbs" (fruits, vegetables, whole grains, legumes, and soy products), low in "bad carbs" (sugar, white flour, processed foods) and with enough of the "good fats" (omega 3 fatty acids) and high-quality proteins.
There are clear benefits to reducing the intake of refined carbohydrates, especially in people who are sensitive to them. The solution is not to go from refined carbohydrates like pasta to pork rinds and from sugar to sausage, but to substitute refined bad carbs with unrefined good carbs.
KF: Tell me more about a good carb vs a bad carb.
DO: Good carbs are whole foods. These include fruits, vegetables, whole grains, legumes, nuts, and soy products in their natural, unrefined, unprocessed forms.
Because these good carbs are unrefined, they are naturally high in fiber as well. The fiber fills you up before you eat too much. For example, it's hard to get too many calories from eating apples or whole grains, because apples are naturally low in calories and high in fiber, which causes you to feel full before you consume too many calories.
Also, the fiber in good carbs causes your food to be digested and absorbed into your bloodstream more slowly. This helps to regulate your blood sugar into a normal range without getting too high or too low.
For example, when whole wheat flour is processed into white flour, or brown rice into white rice, the fiber and bran are removed. This turns a "good carb" into a "bad carb."
Why? Because when the fiber and bran are removed, you get a quadruple-whammy:
• You can eat large amounts of "bad carbs" without getting full. Fiber fills you up before you consume too many calories. Removing fiber allows you to consume virtually unlimited amounts of sugar without causing you to feel like you're full.
• When you eat a lot of "bad carbs," they get absorbed quickly, causing your blood sugar to rise too rapidly. When your blood sugar gets too high, your pancreas secretes insulin to bring it back down. However, it may go down below where it started, causing low blood sugar (hypoglycemia). By analogy, when you pull a pendulum to one side and let it go, it doesn't stop at the mid-point; it continues an equal distance to the other side.
When your blood sugar gets too low, you feel tired, lethargic and a little crabby. There's a good temporary fix for those bad feelings--more bad carbs! This creates a craving for more "bad carbs" to raise your blood sugar in a vicious cycle.
• When your body secretes too much insulin, it accelerates the conversion of calories into triglycerides, which is how your body stores fat. Thus, when you eat a lot of "bad carbs," you consume an excessive number of calories that don't fill you up, and you're more likely to convert these extra calories to body fat. Insulin may also cause your body to produce more of an enzyme called lipoprotein lipase, which increases the uptake of fat into cells, leading to weight gain.
• When your body secretes too much insulin, it may lead to insulin resistance and even diabetes. Insulin binds to what are called insulin receptors on your cells. When your body makes repeated surges of insulin in response to too many "bad carbs," the receptors become less sensitive--a little like Aesop's fable of the boy who cried wolf--as if the insulin receptors were saying, "Oh, not more insulin again, just ignore it." Like a heroin addict who requires more and more of the drug to get the same feeling, insulin resistance causes your body to make more and more insulin just to maintain the same effect on your blood sugar. Over time, this may lead to type 2 diabetes. Too much insulin also enhances the growth and proliferation of arterial smooth muscle cells, promoting atherosclerosis and clogging your arteries.
This doesn't mean you should never eat bad carbs. I do, in moderation. When I eat bad carbs, I try to consume them along with good carbs and other high-fiber foods. That way, the fiber in the good carbs will also slow the absorption of the bad carbs.
KF: Does it make a difference if the protein in our diet is vegetarian or animal?
DO: Yes. To paraphrase Gertrude Stein, a calorie is a calorie is a calorie in its effects on weight but not on health. Interestingly, there have been a few "vegetarian Atkins diet" studies published recently, which is a little like putting lipstick on a pork rind...
KF: What's the danger in a high animal protein diet? Is animal fat any different than vegetable fat (like oils or avocado)?
DO: Diets that are high in animal protein are usually high in saturated fat, which promotes both heart disease and cancer. A recent study reviewed by Dr. Steven A. Smith in The New England Journal of Medicine found that high-protein, low-carbohydrate diets accelerate atherosclerosis (blockage in arteries) through mechanisms other than traditional risk factors such as changes in cholesterol and triglycerides.
Fat (from any source) has nine calories per gram, whereas protein and carbohydrates have only four calories per gram. Thus, when you eat less fat, you consume fewer calories even if you eat the same amount of food--because the food is less dense in calories.
Also, too much protein, especially animal protein, puts a strain on your liver and kidneys and promotes osteoporosis. When your body excretes too much protein, it excretes too much calcium along with it. Too much animal protein, especially red meat, has been linked with significantly increased risks of heart disease, prostate cancer, breast cancer and colon cancer.
For example, a study published last year in the Archives of Internal Medicine reported the findings from a half-million people in the NIH-AARP study that consumption of red meat was significantly associated with increases in total mortality, cardiovascular mortality and cancer mortality.
Studies show that measures of cardiovascular disease rather than just risk factors show that people on average become worse on an Atkins diet. For example, a recent study published in the Journal of the American Dietetic Association by Miller et al showed that flow-mediated vasodilation (a measure of heart disease), LDL-cholesterol and inflammation worsened on a high-animal-protein diet but improved significantly on a low-fat, whole foods, plant-based diet.
KF: How should one eat in order to lose weight?
DO: Mindfully. It's not just what you eat, but also how you eat that matters. Have you ever eaten a bag of popcorn while watching an intense movie? All of your attention is focused on the movie--so you may look down and see that the bag of popcorn is empty. You got all the calories but little of the pleasure. In contrast, if you really pay attention to your food, savoring it as you would a fine wine, you have greatly enhanced pleasure with fewer calories. And pleasure is sustainable.
KF: What should be avoided?
DO: As described above, avoid refined carbohydrates, too much fat (especially trans fats which cause weight gain), and processed foods.
KF: Should we count calories? Fat grams? Carbs?
DO: In my experience, if you eat predominantly a whole foods, plant-based diet that is naturally high in fiber and low in fat and in refined carbohydrates, and if you eat it mindfully, you don't have to count anything to lose weight. You feel full before you consume too many calories.
KF: What are some of the health concerns of being overweight?
DO: Being overweight significantly increases the risk of virtually every chronic disease. Some authorities have said that obesity is now overtaking smoking as the most preventable cause of premature death.
KF: How do you break through cravings for unhealthy food, because they really do have a hold on most of us!?
DO: As you begin to eat more healthfully, your taste preferences change. You begin to prefer foods that are more healthful. And you connect the dots between what you eat and how you feel. Because these mechanisms are so dynamic, most people find that the feel so much better, so quickly, it reframes the reason for changing from living longer to feeling better. And feeling better is sustainable; risk factor modification is not.
KF: What is a reasonable rate of weight loss?
DO: In most cases, no more than three pounds/week.
KF: What if we want to lose weight faster; is there a healthy way to do it?
DO: Do more exercise and meditation and eat smaller amounts of healthy foods and less salt. Regular exercise not only burns calories, it also raises your basal metabolic rate, the number of calories you burn while at rest. Thus, exercise helps you lose weight even when you're not exercising. Do some strength training as well as aerobic exercise. Walking a mile burns even more calories than running a mile. Exercise in ways that you enjoy, then you're more likely to do it. If it's fun, it's sustainable.
KF: If someone is too busy to cook, and is in a big hurry, what is the best and most affordable approach?
DO: There are more and more healthy prepared and frozen meals on the market. Eat with your friends and take turns shopping and cooking--not only does it save time, but when you fill your heart with the love of friends and family in a shared meal, you have less need to overfill your belly.
For more information: www.pmri.org
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