Why People Crave Fatty Foods

Long ago, when humans were hunters and gatherers, be­fore we learned to cultivate the land and raise our own food, we relied on our stores of fat to get us through long periods when food was not readily available. To survive, our bodies had to become adept at storing fat. Without it, we would not have survived to today.

Life was hard. Humans had to battle the elements without the luxuries of heating, electricity, and manufactured cloth­ing. We had to hunt for our food instead of buying it at the supermarket. We had to build fires if we wanted to cook our food, and we certainly couldn’t drive anywhere. We walked, or ran for our lives, or chased, or climbed, or swam. If we were lucky, once in a while, we ate to satiety. Life was phys­ically formidable.

Times have changed, of course. In America, food is plen­tiful for most and automation has largely eliminated the need for physical labor. Although some Americans still squeeze exercise into their days, perhaps a running or jog­ging session a few times a week or a thrice-weekly workout at a health club or gym, such a degree of exercise is minimal compared to what humans once were forced to practice. And many Americans don’t exercise much at all, spending their days in front of computers or behind counters or in comfort­able office chairs.

Yet no one has informed our bodies that food is now far more accessible than it once was, and that survival requires far fewer calories than it once did. Still lagging behind our rapidly changing industrialized society, our bodies remain genetically engineered to handle prolonged periods without food. We aren’t designed for high caloric intakes coupled with low physical activity, yet this scenario describes a way of life for many Americans. The result? An epidemic of obe­sity, and a high rate of chronic disease. Humans may not die from confrontations with large predatory animals very often anymore, but our lifestyles have evolved in such a way that we are confronted with other perils—heart disease, cancer, diabetes, high blood pressure, and cognitive decline, to name a few.

Our ancient origins also explain why women are more likely to put on excess fat stores during pregnancy, espe­cially during the last trimester. Although women still require extra stores of fat for lactation, our bodies may overzeal­ously prepare, in case of a famine. Long ago, to preserve the survival of the species, women had to be able to provide milk, whether food was roasting on a spit over the fire or not.

Because our bodies remain so proficient at fat storage, to maintain good health and a healthy weight, we must adapt our eating habits to match our twenty-first-century activity levels. Our “anti-famine” programming tends to convert di­etary fat readily into body fat. On the other hand, many re­searchers believe that carbohydrates are much less readily converted to fat, and are used more easily as ready energy. Further complicating the picture is the most recent weight-loss fad: the high-protein, low-carbohydrate (some-times called “carbohydrate-controlled”) diet.

According to proponents of these “protein diets” or “low-carb diets,” it is the carbohydrate, not the fat, that is to blame for excess gain. Because so much of the food in the standard American diet consists of processed, refined carbohydrates (white bread, refined pasta, crackers, cookies, and sugar, sugar, sugar), these are indeed an excessive source of calories. Often, re-fined carbohydrates combine with saturated fat or worse, hydrogenated fat, to form “convenience foods” that bear scant resemblance to foods in their natural form, as they first grew on or ambled across the earth.

We’ll talk more about the carb/fat/protein connection in later posts, but for now, suffice it to say that all excess calories will eventually be converted to body fat. You can still gain weight eating carbohydrates without fat, and you can still gain weight eating fat without carbohydrates. Con-trolled caloric intake is the key to weight loss.

Back to fat and heart disease: Some researchers, such as Dr. Dean Ornish, a medical doctor who has studied the effects of low-fat eating to prevent, control, and even reverse heart disease, believe that almost all fat should be eliminated from the diet, and that only about 10 percent of calories in the diet should come from fat sources. Studies Dr. Ornish has conducted reveal dramatic results in heart disease patients put on a very low-fat diet. However, other researchers believe such a level of dietary fat is too low, especially for those who do not have heart disease. Again, proponents of some low-carb diets believe that fat intake needn’t be monitored at all when carb intake remains minimal.

A more mainstream trend, and more heart-healthful approach, we believe, has been to substitute more healthful monounsaturated fats for saturated fats. Keep consumption of all food items (carbohydrates, proteins, and fats) within the ranges displayed by the Mediterranean Diet Pyramid. This will help promote achieving and maintaining ideal body weight. Such a diet may also be easier to follow, since Americans are so accustomed to a diet higher in fat than Ornish’s recommended 10 percent, and many Americans are loath to give up bread, pasta, and other favorite (and healthy!) carbohydrates.

One study, “Dietary Oils, Serum Lipoproteins, and Coro-nary Heart Disease,” reported in the American Journal of Clinical Nutrition, examined the effects of replacing hard fats in the diet with unsaturated fats such as olive oil, versus the effects of replacing hard fats with carbohydrates. Hard fats are fats that are relatively solid at room temperature and are high in saturated fatty acids (such as those prevalent in butter) or trans-fatty acids (such as those prevalent in margarine or other food items listing “hydrogenated” or “partially hydrogenated” vegetable oils on the label). Replacing hard fats with liquid fats resulted in a more favorable blood cholesterol profile than replacing hard fats with carbohydrates, but only if body weight was kept constant. (The study recognized the danger of obesity from excessive fat consumption.)

But fighting this preprogrammed desire for fat is a challenge. If you are craving a hot fudge sundae or a bag of potato chips, chances are you won’t feel satisfied with a bowl of carrot sticks. Fat cravings often diminish when you get out of the high-fat habit. Once you’ve become accustomed to the taste of fresh foods unadorned by excess fat—tender vegetables, juicy fruit, wholesome whole grains, and crisp salads like those so celebrated in the traditional Mediterranean cuisines—the taste of too much fat can become unappealing. And when you just have to have that “fat fix,” for satiety and culinary satisfaction, consider dipping those car-rot sticks, broccoli florets, and red pepper strips into a shallow dish of green olive oil topped with a little pepper. Your low-cal snack just got more interesting!