The Calorie Myth

Calories vary in how likely they are to be stored as body fat. When we eat, our digestive system acts a bit like a traffic cop who tells calories where to go. How Aggressively calories approach this traffic cop determines their chances of being stored as body fat.

The traffic cop directs calories to repair, fuel, or fatten us—in that order. The cop first makes sure we have enough resources to rebuild anything that has broken down. Next, the cop keeps us doing whatever we are doing. Last, the cop seeks to protect us from starving. As long as we have a calm and consistent flow of calories coming into our system, the cop does a great job directing them.

However, as with ordinary civil unruliness, our body does not do its best work when dealing with a bunch of Aggressive requests all at once. When calories approach the traffic cop Aggressively, the cop gets angry, throws its clipboard down, and locks up those calories in fat cells. Right after we eat a plate of pasta and a breadstick, a massive wave of starch starts screaming all at once and the traffic cop says, “Oh, really? To the fat cells . . . all of you!”

To keep calories from being locked up in our fat cells, we don’t need to worry about eating less food. Our body is fine with a lot of food—it is the Aggressive food that annoys it. Five hundred calm calories creeping into the bloodstream over many hours are less likely to be stored as body fat than five hundred Aggressive calories rushing in all at once. Anytime the body has more calories available than it can deal with at one time, it stores them as body fat. That is why the glycemic index and glycemic load have become all the rage.^* These handy measures of calories’ Aggression are like the Most Wanted signs at the post office—they highlight the most dangerous Aggressive offenders.

To best understand calories’ Aggression, glycemic index, and glycemic load, we first need to understand how our body fuels itself. Our body doesn’t run on the food we eat—most often it runs on glucose, a sugar our body creates from the food we eat. That may seem like a meaningless distinction, but it is not.

Body-fat storage is not caused by eating a lot of food. Body-fat storage is triggered as a response to eating food that causes us to have more glucose in our bloodstream than we can use at one time. The more Aggressive calories are, the faster they increase the levels of glucose in our bloodstream. The faster calories increase our glucose levels, the more likely we are to have more glucose than the body can deal with at one time. That’s when the traffic cop shuttles the excess into our fat cells.

The distinction between “a lot of food” and “a lot of glucose right now” is important. We can eat pounds and pounds of food and avoid pounds and pounds of body fat if the glucose the food generates does not exceed the glucose level our body can accommodate right then. That’s the primary reason why the glycemic index, glycemic load, and low-glycemic diets like the South Beach Diet and the Atkins Diet work for so many people. These tools help people avoid excessive levels of blood glucose/blood sugar, a common trap that’s easy for us to fall into, as our body needs surprisingly little glucose yet the normal Western diet is full of foods that spike blood sugar.

Researchers and authors Steve Phinney, MD, PhD, and Jeff Volek, PhD, RD, share a fascinating detail: our body has about 40 calories worth of glucose in circulation at any given time. “This means that when you digest . . . a cup of mashed potatoes or rice, most of the 200 calories of glucose entering the bloodstream . . . has to be rapidly cleared to someplace else to keep blood sugar in the normal range.”⁷³ That “someplace else” is generally our fat cells. So if we want to keep those calories out of our fat cells, we would be better off eating foods that are less Aggressive.

Fortunately, we don’t need to worry about memorizing the glycemic index or glycemic load of foods because SANE eating prevents excess glucose from getting into our bloodstream. If we stick to increasing the amount of water-, fiber-, and protein-packed high-Satiety foods we are eating, we will automatically eat low-glycemic-index foods, ensure a low glycemic load, store less body fat, and lower our risk of coronary heart disease, diabetes, unhealthy cholesterol levels, and cardiovascular disease.^*