Calories are Complicated!
Last June, I wrote a post, entitled “Is a Calorie Just a Calorie?” in which I discussed an interesting food study, reported on in The Washington Post. In this study, scientists examined the effects of various foods—potatoes, nuts, yogurt—on weight gain/loss and discovered that these effects were different than what would be expected, given each food’s calorie count.
Most importantly, this study demonstrated that weight loss is a lot more complicated than just “calorie in; calorie out.”
Recently, Mark Bittman interviewed Marion Nestle, who is Paulette Goddard Professor in the Department of Nutrition, Food Studies, and Public Health at New York University and who co-authored the 2012 book, Why Calories Count, with Malden Nesheim.
Bittman’s report of this interview, once again, points to the difficulties of just counting calories as weight-loss strategy. To summarize:
A calorie is a measure of the energy that comes for a food source. For example, a gram of fat has 9 calories while a gram of protein or carbohydrate has 4 calories.
Theoretically, then, we should be able to count calories to help us calculate what we should or should not eat, right? Wrong.
Calories change as they enter the body so measuring them prior to eating can’t accurately tell you how they’re going to affect your body.
Nestle says that while it’s true that “studies that have measured calorie intake, that have put people on calorie-reduced diets and measured what happened, show no difference in weight loss based on composition of the diet…no one lives under experimental conditions, and foods are complicated mixtures: fiber makes a difference and form makes a difference.”
And our individual bodies make a difference. Nestle again: “There are dozens of factors involved in weight regulation. [For example, it’s] hard to lose weight, because the body is set up to defend fat, so you don’t starve to death; the body doesn’t work as well to tell people to stop eating as when to tell them when to start.”
So it’s complicated.
And where does that leave us dieters? Bittman suggests that the real question should be “What can I eat to keep from putting on weight?” And you and I already know that answer to that one: lots of fruits and vegetables.
Finally, Nestle and Nesheim show us how “political” the calorie really is. Their recommendations to help make our society healthier all boil down to our politicians enacting better food legislation and policy. They say we need
- A farm bill that’s designed to support healthier diets and make them cheaper.
- School lunches based on fresh foods.
- Food assistance programs that give people greater access to healthier foods.
- An improved food-safety system.
- Policies that make it possible for people to get into farming.
- Improved food labelling.
- No food marketing to children.
- Elimination of health claims on food packages unless they’re backed up by universally accepted science.