The Thinker

Glycemic Junk Science

Let us add this report to the list of studies that really do not tell us anything, but do sell newspapers.

When it comes to losing weight, the number of calories you eat, rather than the type of carbohydrates, may be what matters most, according to a new study.

The findings, published in the American Journal of Clinical Nutrition, suggest that diets low in “glycemic load” are no better at taking the pounds off than more traditional — and more carbohydrate-friendly — approaches to calorie-cutting.

The concept of glycemic load is based on the fact that different carbohydrates have different effects on blood sugar. White bread and potatoes, for example, have a high glycemic index, which means they tend to cause a rapid surge in blood sugar. Other carbs, such as high-fiber cereals or beans, create a more gradual change and are considered to have a low glycemic index.

If you put 8 gallons of gas in your car and it gets 20 miles to the gallon, you can expect the car to go 160 miles, plus or minus a bit. It is the energy in the gasoline, the terrain and traffic your car will traverse, and the efficiency of your car in transferring that energy into work that determines how far your car will go.

Your body is an engine too. It is unimaginably more complex than an automobile, but it is still an engine. When you ingest food, its calorie content is translated into amount of energy that your body will receive. If you take in more calories than you expend, you will gain weight. If you take in fewer calories than you burn, you will lose weight. At its most pragmatic level, it’s just math:

Future weight = current weight + ( some constant x ( calories in – calories expended ) )

If you choose 400 calories to come from donuts made with refined sugar and bleached flour as opposed to 400 calories from a high fiber, low glycemic cereal, you are still consuming the same amount of energy.

You can get fat by eating all healthy foods; you just have to eat enough of it. If you gorge yourself on enough salads, you will gain weight. Given the low density of calories per serving with salad, it is much harder to gain weight this way, but it is still possible. That is in part why dieticians recommend consuming whole foods.

Why does a study like this make the news? I think it is because so many of us who are overweight or obese are still hoping, in vain, for a painless method to weight loss. Right now diets emphasizing low glycemic foods, like the South Beach Diet, are in.

Now there are some upsides to eating foods with a lower glycemic index. Most likely these food are healthier for your body. A donut does not have much in the way of nutritional value because most of the good parts, like the fiber, have been removed. Whole foods in general are likelier to have more fiber as well as more vitamins and minerals than junk food. (Many junk foods though are needlessly fortified.) Eating many of these foods may technically be better for your body. It may provide more of what the body needs to carry out vital things like replacing blood cells. Nevertheless, by itself they cannot be a solution to weight loss.

If you want to lose weight, you already know what to do: take in fewer calories than you will burn and exercise more. Exercise burns more calories, but if you eat more calories to make up for the increased exercise you are not going to lose weight.

The real root of our obesity epidemic is that American capitalism has succeeded in creating foods that we crave, and making them readily available at inexpensive prices. Our behavior is not that different from my cat’s behavior. He has his high fiber, nutritionally optimized cat food, which does not taste good. (This is probably just as well, or he would eat more of it and get fat.) On the other hand, he can grub for handouts at mealtime, which is one of his favorite hobbies. He eats the cat food if he has to, but he does not prefer it. Unlike my housecat though, you do not have these restrictions. You can satisfy your cravings with out much difficulty.

As part of my own healthy eating strategy, I do my best not to bring the foods that I crave into my house in the first place. Having them readily available simply adds to my temptation to succumb and consume them. This strategy is not easy. When I hit the grocery store, the shelves are replete with things I want to eat. It takes discipline to avoid purchasing the sorts of foods I want but should not eat. (It helps to go after a meal.)

If you truly want to lose weight then you had better count those calories and understand portion sizes. You need to join Weight Watchers or some group like it; peer pressure can be a terrific motivator. You have to incorporate healthy practices into your life and be consistent about it. Nonetheless, your human nature and society will conspire to trip you up. Life may seem a lot less joyful by disciplining yourself this way, but it is the only way to be healthy. Nothing comes free. If you want a thin and healthy body, you have to consume a lot less and exercise a whole lot more. If you cannot make this choice then be prepared for host of preventable maladies as you age.

Now, I am off to the gym.


Leave a Reply

Switch to our mobile site