Protein and Food Consumption

I noticed when I adopted the The Protein Power Lifeplan
way of eating that I was finally able to eat regularly spaced meals without getting hungry between them. Prior to that, I can’t remember a time in my life when I wasn’t fighting the urge to snack between meals.

In dietary circles, the ability of food to satisfy your hunger is referred to as the satiety factor. Some researchers claim satiety is tied to the feeling of fullness you get from bulkier foods, but my experience is that high fiber foods do not necessarily satisfy my hunger. They make me feel full, but still hungry. There’s always room for another slice of that fiber-rich pumpkin pie.

Low carb advocates often cite the satiety factor of their diet, as I have done in the first paragraph. Some point to the higher percentage of fat in the diet than the typical low-fat diet emphasized by most doctors, making the claim that you cannot gain weight if you eat a low carb diet with plenty of fat. But some people do gain weight that way, so something else may be at work.

When I started Protein Power, I calculated my daily minimum protein requirement, as the book recommends. I was surprised at how much food I could eat. With 25 – 30 grams of protein per meal as a minimum, that meant a hearty bacon and eggs breakfast of 3 eggs (18 grams) and 3 slices of bacon (9 grams). My usual breakfast routine was a toasted bagel, then a snack before lunch because by 10 AM I was very hungry. But after eating the eggs and bacon mentioned above … I was full, and remained so until lunch time.

As the title of the book suggests, Protein Power is about getting the right amount of protein as well as reducing carbohydrates. It works for me. And it may be the protein that satisfies, rather than just the increased fat.

Nutritional ecologist Professor David Raubenheimer of New Zealand’s Massay University, recently conducted a study on primate eating habits in collaboration with other experts. Studying the Bolivian rainforest spider monkey, Professor Raubenheimer found the monkey’s food intake increased when low protein food sources were the only ones available.

The findings, published in the latest issue of the journal Behavioural Ecology, reinforce the theory that humans and other primates are physiologically predisposed to maintain a constant level of protein in their diets. But when the range of foods available to them is low in protein (yet high in fats and carbohydrates) they are compelled to eat greater quantities in order to maintain correct protein levels.

I think this explains the satiety issue better, and gives an indication of why some people experience weight gain even on a low carb diet. If they aren’t meeting their body’s protein requirements, they will be hungry. And hungry people eat more.

Exercise Doesn’t Shed Pounds?

Gary Taubes, the nationally acclaimed science writer, explains why exercise and weight loss are not physiologically linked:

The one thing that might be said about exercise with certainty is that it tends to makes us hungry. Maybe not immediately, but eventually. Burn more calories and the odds are very good that we’ll consume more as well. And this simple fact alone might explain both the scientific evidence and a nation’s worth of sorely disappointing anecdotal experience.

The New York magazine article is a good read, and includes Taubes’ signature style of including historical perspective to frame the issue. And he gets to the underlying philosophy behind the “calories in / calories out” theory of weight loss: the idea that the body is a thermodynamic black box that has to respond to the balance of calories taken in and calories expended.

But we are not gasoline engines. Taubes explains that the thermodynamic black box theory (TBBT) fails to take into account the role of fat tissue in our metabolism. Studies showed fat people maintaining or gaining weight while eating less than thin counterparts. But the thin people were more active. The correlation seemed to support the TBBT theory. But studies of overweight people who increased activity substantially, including a controlled study where Finnish researchers trained overweight men and women to run a marathon, showed that they maintained their weight.

Overweight people who have tried the “diet and exercise” remedy can commiserate with their Finnish brothers and sisters.

Taubes relates that our bodies have been shown to try and maintain certain levels of blood sugar, hormones, etc. We have evolved to try and counteract the entropy of our environment and gradual breakdown of our bodies. Our survival depends on it:

The key is that among the many things regulated in this homeostatic system—along with blood pressure and blood sugar, body temperature, respiration, etc.—is the amount of fat we carry. From this biological or homeostatic perspective, lean people are not those who have the willpower to exercise more and eat less. They are people whose bodies are programmed to send the calories they consume to the muscles to be burned rather than to the fat tissue to be stored—the Lance Armstrongs of the world. The rest of us tend to go the other way, shunting off calories to fat tissue, where they accumulate to excess. This shunting of calories toward fat cells to be stored or toward the muscles to be burned is a phenomenon known as fuel partitioning.

What is the mechanism for storing calories as fat? Insulin, working in concert with an enzyme, lipoprotein lipase (LPL), determines if energy should be burned or stored as fat.

Low carb dieters know that one effect of eating a low carb diet is to even out the insulin response. Those of us with insulin resistance also know that as we even out the insulin response, our cells become less resistant to the insulin in the bloodstream, and more of the glucose in our blood is used for muscular energy rather than stored as fat.

A low carb diet is more than a weight loss diet; it is a lifestyle choice that leads to more stable weight for a lifetime. This is possible because, unlike exercise, eating lower carbohydrates in your daily diet aids in the feeling of being satisfied with the amount you have eaten. When you aren’t hungry, its easier to not reach for that snack.