Friday, September 6, 2013

Why Are You Fat?

According to the CDC, about 36% of U.S. adults are obese and as of 2010, about 23% of the people in Massachusetts are considered obese. Their definition of obesity is based on the Body Mass Index (BMI), though they acknowledge that is not a fully accurate way of assessing individuals, such as athletes. These obesity figures do not include those people who are only overweight, though that would raise the percentage significantly of those Americans who weigh too much.

Each year, these figures continue to increase but why is that so? Why are so many putting on extra pounds? We think we understand the reasons but is that really the case? Could we be looking at all of this in the wrong way? That might very well be the case.

Scientific American recently published a special Food Issue (September 2013), which contains nine fascinating articles about food related issues, from How (and Why) To Eat Invasive Species by Chef Bun Lai to The First Cookout, an interview with Richard Wrangham. Two of the articles dealt with issues of weight gain, offering interesting takes on what is often considered "common knowledge." We need to start looking at some of our treasured beliefs, to reassess what we think, and hopefully find a better path to weight loss.

The first thing we need to do is to reconsider the calorie, understanding that the calorie counts on food labels are not accurate indicators of the amount of calories an individual will receive. Rob Dunn, a biologist at North Carolina State University, penned an article, Everything You Know About Calories Is Wrong, explaining the problems of calorie counts. Calorie determination is based on a 19th century system that uses averages, ignoring numerous important factors such as the effects of digestion and cooking.

Dunn states: "To accurately calculate the total calories that someone gets out of a given food, you would have to take into account a dizzying array of factors, including whether that food has evolved to survive digestion; how boiling, baking, microwaving or flambeing a food changes its structure and chemistry; how much energy the body expends to break down different kinds of food; and the extent to which the billions of bacteria in the gut aid human digestion and, conversely, steal some calories for themselves." (p.58) What that means is that two individuals, eating the same amount of calories, will not incur the same amount of calories, so that one person might lose weight while the other might not.

For example, cooking food allows a person to obtain more of the calories in that food than you would if the food was raw. So if two people consumed 2000 calories of food, and one person cooked all his food while the other ate all his raw, the person with the raw food would actually take in less calories. The type of food matters as well. For example, nuts generally are less completely digested than some other foods, meaning you get less calories from them. In addition, each individual is different in their biological make-up, meaning they will take in more or less calories than another person.

What that all means is that a diet that merely counts calories is overly simplistic and potentially doomed to failure. It would explain the frustration some dieters have when seeing others lose weight, on similar amounts of calories, which they can't seem to lose. People need more education about calories, to understand that label calorie counts are probably closer to suggestions than actual facts. At best, those calorie counts might stand as a potential maximum amount that can be derived.

All this discussion of calories though is based on the theory that weight gain is due to an imbalance between calories consumed and calories expended. In short, if you eat too much, ingest too many calories, or are too sedentary, exercising little, then you will gain weight. Most people accept this as a given, yet it hasn't prevented more and more people each year gaining excess weight nor has it prevented an increase in metabolic disorders like Type 2 Diabetes. Why is that so if we know exactly what causes weight gain?

Gary Taubes, co-founder of the Nutrition Science Initiative, in his article Which One Will Make You Fat?, poses an alternative theory of weight gain. He notes that the calorie theory actually never was based on proper scientific studies, being accepted more as a given. It sounds like a logical theory but even those should receive empirical proof of their validity. Gary offers another potential theory, which he believes deserves to be investigated, and which a few scientists have now started to address in new studies.

Rather than being due to an energy imbalance, weight gain could be instead due to a hormonal defect, with the primary offender being carbohydrates. The science is interesting. The carbohydrate glucose causes the pancreas to secrete insulin, to prevent glucose levels from being too high. The insulin causes some of that glucose to be stored as fat for some future use, which means that if insulin levels remain high, then you gain more and more fat. By avoiding or limiting carbohydrates, you prevent this fat storage from occurring, and that might be the best way to avoid gaining weight. So worrying about calorie intake might not be as important, as where those calories come from.

More scientific studies are needed to resolve this conundrum, but just the fact that we are questioning "common knowledge," which never actually was proven, is a major step forward. If you are having trouble losing weight, and you believe you are doing everything right, then it is time to reconsider the basis of your beliefs.

1 comment:

Frederick Wright said...

There are certainly a great many complex factors at work. Instead of focusing on what foods/behaviors might make me fat, I simplified my approach and simply emulate the eating habits and lifestyle of those people who are trim. The French enjoy all the same wonderful, rich, soul-nourishing foods that I love and yet remain quite healthy.

So I've given up my car, I live in an walkable urban environment, work just seven hours per day (no more, ever), take at least one month vacation every year, and severely limit my intake of processed/chemically enhanced food.