Public health experts agree that obesity is having a devastating impact on Americans' health. And most would also agree that people eat far too much sugar. But only a few experts go as far as Dr. Robert Lustig: According to the pediatric endocrinologist and author of a controversial new book, sugar is at the root the obesity epidemic.
Lustig's book, Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease (Hudson Street Press), promotes his theory that obesity rates in the United States have soared because we eat too much sugar, especially fructose. In contrast, many health experts say that while too much sugar is clearly bad, the major cause of obesity is that we consume more calories than we expend—mostly due to a high-fat diet.
TakePart asked Lustig, a professor of pediatrics at the University of California, San Francisco, to explain his ideas:
TakePart: Most people believe that we're fat because we take in more calories than we expend. Are you saying the specific components of your diet matter more?
Dr. Robert Lustig: A calorie burned is a calorie burned. So if you burn 100 calories sleeping, that's the same as 100 calories burned by 15 minutes of jogging. But a calorie eaten is not a calorie eaten. Take protein: Protein requires twice as much energy as carbohydrates to break down and to be able to utilize it for energy. Take trans fats versus omega-3s: Omega-3 fatty acids are healthy, but trans fats will kill you.
This whole "a calorie is a calorie" business—unfortunately, I have a potty mouth and I know I shouldn't say this but I can't help it—it's bull----. The problem is, this is what dieticians and the whole federal government continues to say. It could not be further from the truth. We've had 30 years of this and it doesn't work. Once you believe that a calorie is not a calorie—once you accept that premise and get past it—everything opens up.
TP: What parts of our diet should people focus on for obesity prevention and better health?
RL: Getting fat out of your liver has to be priority one. And the only way to do that is stop eating the substances that cause it. One is alcohol. One is trans fat. One is branch-chain amino acids, which you find in corn-fed beef—the marbled [fat in that] beef which gives it the flavor. But the Big Kahuna is fructose.
We know now that if you get hepatic insulin resistance it drives all the [health] consequences: obesity, heart disease, hypertension, high cholesterol, diabetes. You have a five-times higher propensity for every one of those diseases. Fatty liver disease was never described before 1980; it's 32 years later, and one-third of all Americans have it. That is the biggest epidemic ever.
TP: You say that fructose is worse than glucose. Why is it worse?
RL: Fructose does not stop hunger. Glucose stops hunger. There was just a paper that came out in the Journal of the American Medical Association that showed this. Fructose doesn't stimulate satiety. You can eat all this fructose and still be hungry.
TP: Should people cut out sugar entirely? Is there a safe amount?
RL: Cut added sugar. I am not against fruit. Fruit has fiber, it has micronutrients. Whole fruit is not a problem. The reason fruit is okay is because of the fiber.
TP: Why do you believe governments should step in with regulations regarding sugar content in food?
RL: Sugar is an addictive substance. We have a lot of data to support that. In animals, it's across-the-board, slam-dunk addictive. In humans, it's harder to prove these things....We have correlates but not causation. But the data go in the right direction for addiction. If we accept that alcohol is addictive, it shouldn't be a big stretch to believe that sugar is addictive in some people. That's why we need regulations. No addictive substance on the face of the earth has been able to be dealt with by personal responsibility; we need personal and societal interventions.
TP: What kind of regulations are logical?
RL: Taxation doesn't cost anything to implement. It's effective. The big problem is no one wants to be taxed. The government institutes the tax and instead of using the tax for what it's supposed to be used for—obesity-prevention programs—it goes into a general fund. It never gets where it's supposed to go. People are very much against government because you can't rely on government to do the right thing.
TP: Do you think we'll eventually have some government action to reduce sugar consumption?
RL: Ultimately this is going to go to the courts in the exact same way as tobacco addiction issue went to the courts. The blueprint is very clear. It has to go to the courts. This is a public health crisis. All significant public health advances involve and require the use of laws.
Do you think sugar consumption is a big part of America's obesity epidemic? Do you think it should be regulated, like alcohol and other addictive substances?
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Shari Roan is an award-winning health writer based in Southern California. She is the author of three books on health and science subjects.