NNAMDI: Many of us have been led to understand that weight gain or loss is simply a matter of willpower, our ability to restore balance to that equation of the calories that go in our bodies and the calories that we use and go out. You've done a lot of research that suggests our basic understanding of that equation is off kilter. How so?
LUDWIG: … Very few people can lose weight over the long term with low-calorie diets. And those who can't are blamed for lack of discipline and willpower. So, according to an alternative view, weight is controlled like body temperature and a range of other biological functions. Eating too much refined carbohydrate has, by this theory, raised insulin levels and programmed our fat cells to suck in and store too many calories. When this happens, there are too few calories for the rest of the body. So the brain recognizes this and triggers the starvation response. We experience that as becoming excessively hungry and our metabolism slows down. ... Eventually we succumb to hunger and overeat. So a better approach, if this theory is correct, is to address the problem at its source by cutting back on the foods that are over-stimulating our fat cells: the refined carbohydrates like grains, potato products, concentrated sugars, especially the refined grains. And by eating this way, we can basically ignore calories and let our body-weight control systems do the work.
NNAMDI: Is it oversimplification to say that your research suggests we’re getting hungrier because we’re getting fatter?
LUDWIG: [No,] that’s right.
Ludwig and co-author Mark Friedman wrote about this in a New York Times article last month headlined “Always Hungry? Here’s Why,” saying that the “simple solution” ingrained in people who want to lose weight “is to exert willpower and eat less.”
The problem is that this advice doesn’t work, at least not for most people over the long term. In other words, your New Year’s resolution to lose weight probably won’t last through the spring, let alone affect how you look in a swimsuit in July. More of us than ever are obese, despite an incessant focus on calorie balance by the government, nutrition organizations, and the food industry. … As it turns out, many biological factors affect the storage of calories in fat cells, including genetics, levels of physical activity, sleep, and stress. But one has an indisputably dominant role: the hormone insulin.
The food industry didn't necessarily focus on calorie counts until recently, but it has definitely embraced it now. Twix and Oreos come in 100-calorie packs. Coke tells you exactly how to burn its calories off. It’s better than nothing, right? Here’s my foray into the realm of nutrition ideas: Eating based on calories is a problem. That’s what I should’ve told T.J. Holmes. It’s really an aggregate of what many nutritionists and writers are saying right now, but: Calorie counting doesn’t work for most people, and it’s manipulated by companies marketing junk. It’s not a good way to think about food.
Highly refined carbohydrates—chips, crackers, white bread, soda, rice—spike our blood sugar. That spike makes the pancreas produce tons of insulin. That insulin tells our body to store energy as fat. Subsequently, as Ludwig and Friedman write in the current Journal of the American Medical Association, “energy expenditure declines and hunger increases, reflecting homeostatic responses to lowered circulating concentrations of glucose and other metabolic fuels. Thus, overeating may be secondary to diet-induced metabolic dysfunction.” That is, refined carbs make us eat more, which makes us fat, which makes us eat more, and so on.
NNAMDI: James, the last time you joined us we talked about the addictive power of foods, whether Oreos are really kind of maybe like crack cocaine. It seems that part of this conversation is about a habit many of us develop in thinking that all calories are just calories, regardless of their sources. There are a lot of people out there now saying, no, all calories are not created equal. What are they saying and why is this significant?
HAMBLIN: It goes right in line with what Dr. Ludwig is saying, that certain calories will cause fluctuations in the body's hormones and blood sugar levels, that will only augment future hunger. So you might be able to temporarily eat a low calorie diet of high-sugar foods but it's going to be unsustainable, you're not going to feel good. You're probably going to feel constantly hungry. And after a few weeks, probably go back to eating more. Whereas if you focus on eating a more balanced whole food diet, you will sustain that longer. And ultimately, you know, we're not proposing that this is overturning the first law of thermodynamics. You will need to burn more calories than you consume [in order to lose weight]. But it's about where you focus that intention of eating. If you think about the calories, I think you tend to make choices to say, well, I can only eat 200 calories now, I'd really like to get that as the most delicious 200 calories possible. I'm going to eat 200 calories of ice cream or soda. ...
LUDWIG: This is, of course, an argument the food industry loves because, by it, there are no bad foods.