Why Your Body Resists Weight Loss

Last week, I wrote about the weight-loss program of Dr. Daniel Kirschenbaum as outlined in his book, "The Nine Truths about Weight Loss." One of the nine "truths," according to Kirschenbaum, is that your body will resist permanent weight loss because of biological forces that have evolved to make sure that we continue to exist as a species. A reader asked me to explain further about these built-in survival mechanisms.

Understanding why our bodies were designed to hold on to our fat is not meant to give you a cop-out excuse not to lose weight but to help you be more successful in controlling your weight.

Once you realize that you are not a "weak" person, a glutton, or someone with poor willpower, but rather a normal human being with a body whose main priority is survival, then you can let go of negative self-blaming attitudes and devise a meaningful action plan to deal with those biological forces.

Kirschenbaum gives three reasons we are literally born with a sweet tooth. "When we are hungry, sugar provides the quickest antidote... When humans or other animals are starving, they consistently show heightened preferences for very sweet foods. This, again, shows the body's orientation to satisfy extreme hunger and food deprivation quickly and effectively with sugar.

"Sweet foods are safe foods. Can you think of any examples of wild fruits or berries or vegetables that are sweet and also dangerous to eat? Probably not. If you find something hanging from a tree and it tastes sweet, it is almost certainly safe to eat. On the other hand, sour or bitter fruits or vegetables are much more likely to be poisonous.

"The body is programmed to eat large amounts of sugar or sweet foods whenever they are available. This made sense for hunter-gatherers; if they found something that tasted sweet, their bodies wanted to encourage them to eat large quantities of it."

Honey is a prized find in primitive societies like the Aborigines of Australia and the Bushmen of South Africa. They go out of their way to find the sweet stuff and consume large quantities of it.

Action plan: Don't skip meals so you don't become hungry and seek out sugary foods. Avoid processed foods high in sugar because the more you eat them, the more your body wants them.

As revealed by the practices of primitive hunters, human beings like fatty food. The fattest parts of an animal are eaten first. Animal bones gathered from caves inhabited by Neanderthal men show that the marrow was carefully removed. This makes sense because animal fat is easier to eat than tough muscle. It is also the part that is the most flavorful. Intra-muscular fat makes meat juicier and moister. Lastly, fat is the densest source of calories at nine calories a gram compared to four calories for protein and carbohydrates, respectively.

Bottom line: Eating fatty food may have served its purpose before when food sources were scarce, but in today's society of abundance, food high in fat contains far more calories than your body can handle.

The tendency to go on an eating binge doesn't just happen to people with bulimia (an eating disorder wherein someone binges and then vomits the food) or compulsive eating. Binge eating seems to be a survival mechanism. It is triggered by deprivation and periods of not having enough to eat. Since food was not always easy to find, a big appetite was advantageous. Primitive men would eat and store as many calories in one sitting as they could.

Bottom line: If you go on a starvation diet, a binge will not be far behind. Cut back on calories moderately so you don't feel deprived and trigger an eating binge.

At the Buffet Table
Food was not always as readily available as it is now. So if we were created like koalas that only eat eucalyptus leaves, we would have become extinct. We are designed to eat almost anything edible on this earth.

According to a report in the Tufts University Health and Nutrition Newsletter, human beings are genetically programmed for "sensory specific satiety." This simply means that if you keep eating the same kind of food, you get sick of eating it. The report explains it another way: The second chocolate bar never tastes as good as the first and might go unfinished.

That's why you eat more when you eat "family style" in a restaurant where everyone orders something different and you share all the dishes compared to when you order your own main course. This is the reason you pig out at an all-you-can-eat buffet.

It explains why people lose weight on one-type-of-food diets like the Cabbage Soup Diet or on a highly restrictive diet like the Atkins Diet, which forbids most carbohydrates. There is nothing magical about eating cabbage or protein only. No matter how much you love adobo, if you have it for breakfast, lunch and dinner, you will end up disliking the very sight and smell of it. You end up eating less from sheer boredom of the diet. You might think that these types of diets are the answer to all your weight loss problems, but unfortunately, your body will rebel.

Biological psychologist Marcia Pelchat tells of an experiment where people who drank nothing but a vanilla-flavored milk supplement drink and water for five days started to crave the opposite type of food flavor like steaks and pizzas rather than the same type of food flavor like ice cream, cookies and cake. Pelchat notes cravings might be the body's way of encouraging you to eat a more varied diet.

Now I know why I was never successful with the Atkins Diet. After a few weeks of eating mostly meat, eggs and cheese, I would crave for the opposite--sweet and starchy food.

Bottom line: Avoid buffets if you are trying to lose weight. Eat simple meals. Researchers have found out that people who do not eat a large variety of food (except fruits and vegetables) have an easier time losing weight.

This means it's okay to have three kinds of fruit available at home but not three kinds of dessert. Avoid one-type-food diets. You may lose weight initially but eventually, it will backfire on you.

The body cannot tell the difference between famine and a self-imposed "crash diet." It does not realize that you are dieting to look good and lose excess weight. All it knows is that it is in danger of dying. As one weight-loss expert said, your body puts survival above all else, vanity included. To protect you from your own foolhardiness, your body lowers its metabolic rate to conserve energy by setting biochemical changes into motion.

One of the first changes is the activation and multiplication of fat-storing enzymes. The fat cells become more efficient at storing fat and less efficient at losing fat. Some studies have shown that severe dieting can reduce fat-releasing enzymes by 50 percent.

Crash dieting also forces your body to get the extra calories it needs by raiding its fat storage and by cannibalizing its own muscle tissue. The body, in effect, feeds on itself. Less muscle mass means you become less efficient at burning calories. When you go off the diet and eat normal amounts of food (a more typical reaction is to go on a binge), your body reacts by hoarding as much fat as it can just in case the "famine" happens again. No wonder people gain so much weight after a bout of crash dieting. This built-in protective mechanism ensured survival. If it were that easy to lose weight, the human race would have died out long ago.

An analysis of 43 studies on dieting found out that crash dieting doesn't damage your metabolism permanently. However, while your metabolism is struggling to return to normal, you are at risk for gaining even more weight than you originally lost.

Bottom line: Avoid extreme dieting and exercise. Lose weight slowly but surely, but eating properly and exercising regularly.

The Association of Fitness Professionals of the Philippines will hold a seminar on Sept. 21 at the Bahay ng Alumni, UP Diliman. Topics for gym instructors are "Exercise and Infection," "Preventing Foot and Ankle Injuries," "All About Cellulite" and "Why Women Gain Weight." Topics for aerobics instructors are "Kickboxing," "Stretch and Tone," "High-Low Impact" and "Latin Aerobics."

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