Is Sugar Really Making Us Fat?

Dr. John McDougall is a physician, nutrition expert, author of 12 bestselling books, and founder of the McDougall Program. His newest book, The Healthiest Diet on the Planet, challenges the basics of healthy eating. Here, Dr. McDougall shares why sugar isn’t making you fat and how you can eat potatoes and still lose weight.


  1. How likely is it that a meat-eater will get diabetes, heart disease, or cancer over someone who is purely plant-based?

If you follow the diet that I preach, which is a starch-based diet with fruits and vegetables, no dairy, and extremely little meat or none at all, then your chances of getting all the common diseases — MS, rheumatoid arthritis, prostate cancer, colon cancer, breast cancer— are zero compared to U.S. data.


  1. When Americans think of starch, they think of donuts and bread. When you say a starchy, high-fruit diet, what do you mean?

What we are talking about is using common starches, which are rice, corn, potatoes, beans, peas, lentils, and sweet potatoes, as the base of the diet. You can add vegetables and fruits. Some starch-eaters do eat meat, but it is not the ideal food for people.


  1. In the blue zones, they were eating mostly starches, but they were also eating some meat. Is there a safe level of animal products that we can eat without facing grave health problems?

“Is there [a] safe level of animal products?” would be like asking me: “Is there a safe number of cigarettes that I could smoke without getting lung cancer?” These animal foods are not necessary for protein, vitamins, minerals, or anything else. You can get B12 from other processes. Amount is everything. You can take a little bit of arsenic and be fine. But, animal products are toxic in the amounts consumed by Westerners. Animal products are toxic in terms of fat content and cholesterol and the protein is very damaging to the system. They have no dietary fiber, no carbohydrates and they are full of environmental contaminants.


  1. You described cancer in really interesting terms — it doesn’t really occur overnight, but once you get it, you have it forever.

Once you have it you have it, it is not curable, except in a few cases. Common cancers like colon, breast, and prostate, if they are truly cancers (in other words, they spread), then they spread long before you find them. It is just that they are so slow-growing that some are never destined to kill. They can grow so slowly that the cancer doesn’t show up until a person is 100 years old.


  1. If you are diagnosed with cancer, what’s the first thing you should do?

Take the lump out, remove the obvious disease and then you change your diet. In February 2015, the American Cancer Society came out and said that people who had cancer of the breast, colon, prostate, skin, etc., and who changed their diet, lived longer. Therefore, they made a fundamental, general standard recommendation for all doctors to tell their patients that once they have cancer they must change their diet. It is an official policy.


  1. Diets are hard to follow. If I’m overweight, what’s the best way to slim down, get healthy and do it in a sustainable way?

The best way to lose weight and get healthy is to stop eating poisonous foods, which are animal products and oils. We can talk about the historical picture of people who lived on starch-based diets, but just think back 35 years ago to [what life was like in] Vietnam. You saw pictures of thousands of people standing in the town square of Vietnam or Thailand, or Cambodia or China or Japan. You didn’t see one single fat person. Why is that? It is because 90 percent of their diet came from starch, which was rice. The way to lose weight and fix health problems is to stop food poisoning and stop consuming animal products and oil. Instead, live on a traditional, starch-based diet.


  1. We live in an environment now of ease and abundance, where we have engineered most of the movement out of our lives. How do you get toxic food out of your system practically?

As an individual, you just have to avoid it. So, most people don’t go into the Dairy Queens or Burger Kings. Instead, what they do is they make a very simple meal plan. My wife’s and my diet consists of oatmeal with blueberries for breakfast; for lunch we probably have left overs; and about four times a week she makes a bean dish in her slow cooker. It is kind of like a bean soup or bean stew. My wife spends probably less than ten minutes, and, in terms of food or meal preparation, we have two or three meals [for the week].


  1. You talk about food poisoning being animal products and oil, but you don’t say anything about sugar.

Nor do I say anything about salt. The main reason is [that] animal products and oils are the primary toxins. Plus, people naturally don’t like to eat animals or oil. When it comes to salt and sugar, people love them. The reason we love them is because we need them for good health. The tip of your tongue has a taste sense for both.

What I recommend is using a little salt and a little sugar on the surface of the food so you want to eat it. A teaspoon or so of brown sugar on your oatmeal isn’t going to make the difference as to whether you’re healthy or sick, but it may make the difference as to whether you eat it or not. The sugar rots your teeth, it is empty calories, it may raise triglycerides, but it does not cause obesity or Type 2 diabetes, and that’s absolutely consistent with the scientific literature. But, if you eat sugar with fats like the ones found in donuts, then your risk of obesity and Type 2 diabetes increases.


  1. When you skewered the high-protein diet, what was the argument you put forth?

Well, these are low-carb diets where they tell you not to eat starch, which is the diet of human beings. They tell you to eat as many animals as you can stick in your mouth. These diets (like the original Atkins diet, Wheat Belly, and Grain Brain) work by putting you into ketosis. What they really do is make you sick; all that meat poisons you. It causes ulcers and damages your arteries, and it slaughters a billion animals a day on planet earth. Low-carb diets are destroying us. Beef is a hundred times more environmentally destructive than a potato. Low-carb, high-protein diets are just not human diets; they are diets for cats. People are starch-eaters, starchivores, starchitarians. Period.


Dr. McDougall was raised in the Midwest and still loves the traditional dishes of his youth. One of his favorites is his Mashed Potatoes and Creamy Golden Gravy.

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