The movie “Fed Up” is coming out in theatres — just saw Katie Couric doing publicity for it. Despite the popularity of spinning it as a case of corporate greed, I don’t see much corporate villainy here. I do see cheap foods that taste good pushed by government subsidies for Big Agriculture, plus a move to eat on the go. There are two problems with the “calories in, calories out” theory now amply disproved: first, calories of energy absorbed from food are not the same as calories of the same food burned in a bomb calorimeter. And second, the components of what you eat (notably high-glycemic-index carbs) can drastically affect your metabolism and cause you to crave even more, and to use less energy. “Eat less and exercise more” may be very difficult unless you change what you eat.

The New York Times story (also tie-in PR for the movie) goes on to say:

Dr. David Ludwig, the director of the obesity program at Boston Children’s Hospital, argues in the film that [all calories are not the same]. In recent studies, Dr. Ludwig has shown that high-carbohydrate diets appear to slow metabolic rates compared to diets higher in fat and protein, so that people expend less energy even when consuming the same number of calories. Dr. Ludwig has found that unlike calories from so-called low glycemic foods (like beans, nuts and non-starchy vegetables), those from high glycemic foods (such as sugar, bread and potatoes) spike blood sugar and stimulate hunger and cravings, which can drive people to overeat.

While people can certainly lose weight in the short term by focusing on calories, Dr. Ludwig said, studies show that the majority of people on calorie-restricted diets eventually fail. “The common explanation is that people have difficulty resisting temptation,” he said. “But another possibility is that highly processed foods undermine our metabolism and overwhelm our behavior.”

At Harvard Medical School, Dr. Dariush Mozaffarian, an associate professor of medicine and epidemiology whose research was cited by experts in the film, said that the long-held idea that we get fat solely because we consume more calories than we expend is based on outdated science.

He has studied the effects that different foods have on weight gain and said that it is true that 100 calories of fat, protein and carbohydrates are the same in a thermodynamic sense, in that they release the same amount of energy when exposed to a Bunsen burner in a lab. But in a complex organism like a human being, he said, these foods influence satiety, metabolic rate, brain activity, blood sugar and the hormones that store fat in very different ways.

Studies also show that calories from different foods are not absorbed the same. When people eat high-fiber foods like nuts and some vegetables, for example, only about three-quarters of the calories they contain are absorbed. The rest are excreted from the body unused. So the calories listed on their labels are not what the body is actually getting.

“The implicit suggestion is that there are no bad calories, just bad people eating too much,” Dr. Mozaffarian said. “But the evidence is very clear that not all calories are created equal as far as weight gain and obesity. If you’re focusing on calories, you can easily be misguided.”

For more on diet and weight loss:

Getting to Less Than 10% Body Fat Like the Models – Ask Me How!
Starbucks, Jamba Juice Make You Fat
Fat Doesn’t Make You Fat. Government Guidelines Did!
Fructose: The True Villain?
More on “Fed Up”, Sugar Subsidies, and Obesity
Another Study on Diet Drinks
LeBron James Cut Carbs for Lean Look
Why We’re Fat: In-Depth Studies Under Way
Almonds: Superfood, Eat Them Daily for Heart Health
Fish Oil Supplements Ward Off Dementia
More on Diet Drinks: Best Studies Show They Aid Weight Loss
Vani Hari: “Food Babe” and Quack
Cleanses and Detox Diets: Quackery
Sugared Soft Drinks: Health Risk? (and What About Diet Soda?)
Gluten-Free Diets: The Nocebo Effect
Acidic Soft Drinks and Sodas: Demineralization Damages Teeth
Fish and Fish Oil for Better Brain Health
Salt: New Research Says Too Little May Be Unhealthy
Bulletproof Coffee: Coffee, Oil, and Butter for Breakfast?