Tuesday, August 19, 2008

Fit And Fat?

This post was originally posted on Tara Parker-Pope's wonderful blog entitled "Better To Be Fat and Fit Than Skinny and Unfit. Click here for original post.

There are thousands of genes responsible for creating our individual "set points." Set point is a range, which can be influenced to some degree by lifestyle. For instance, someone who is supposed to weight around 150, may weight 120 or 180, depending on feeding and activity levels, but it seems impossible that they could ever weight 400 lbs, since the body speeds or slows metabolism to maintain homeostasis. Similarly, someone who is programmed to weigh around 400 lbs might weigh somewhat more or less, but could never weigh 150lbs, without gutting their guts...and even then, it seems highly unlikely.

The Weight Control Registry documents people who have lost significant amounts of weight and kept it off, but we know that they are a minority of the population, since most people regain lost weight. What we don't know is how many people develop an eating disorder in order maintain the loss.

As a psychologist specializing in weight management, I could tell if someone has an eating disorder by the extent to which they are preoccupied with food, exercise, weight and body image. To maintain a severe weight loss, people generally must live in a state of semi-starvation. A primary psychological symptom of starvation is preoccupation with food. This is for survival, much like if you can't get enough water, all you can think about is finding water, or when sleep deprived, the drive to sleep trumps all else. The NY Times once did a video montage of Mike Huckabee's constant references to food on the campaign trail.

Statistically speaking, a normally distributed bell curve dictates that 68% of people are "average," 14% are somewhat more or less, and 3% are extreme. This holds true for things like height, weight and IQ. BMI arbitrarily splits up the average range, by separating "normal" from "overweight" without any statistical integrity. If someone falls into the 70th percentile for height, do we call them "overheight?" Furthermore, BMI is not a measure of fitness; we would do better to routinely consider measures of endurance and strength.

BMI discriminates against women, since we are genetically programmed to store more fat in hips breasts and thighs, yet are held to the same BMI standards as men.

In this time of cultural abundance, the bell curve has shifted slightly to the right, with obese people becoming more obese … since their genes direct their bodies to store fat in times of abundance. This has been the most significant group of gainers. Perhaps this is for survival of the species, since they could live off their fat longer, if there was a famine. This perspective might offer newfound respect for body size diversity.

On average, most Americans have gained approximately 20 pounds in 20 years, which is a pound a year, or 10 calories per day....which is not even measurable. One explanation is our aging population, since some gain is normal. Another explanation is the increased availability of food and health care, which means that we are maximizing genetic potential for height, weight, and even IQ. Nobody talks about the corresponding increase in HEIGHT, which is a fact as much as the increase in weight.

In fact, a very influential cancer study earlier this year found that weight was the #1 correlate for many cancers; alcohol was the 2nd, and the 3rd was height! Media never espoused that taller people had more cancer - perhaps because on the surface, it seems absurd. However, a chart of international ages of deaths revealed that Americans were among the longest living people, while Indians had much shorter life expectancies. Indians also had lower BMI's, so what was happening is that better nourished countries produced people who were taller and heavier, and lived long enough for cancer to develop. Indians never lived long enough for slow growing deadly cancers to develop!

There's plenty of solid research suggesting that fitness is more important than weight, but stigmatizing overweight people offers permission to discriminate. It also fuels the 40 billion dollar diet industry, by making us hate ourselves, and then selling faulty remedies which fuel yo-yo dieting, which may negatively impact cardiac fitness, insulin sensitivity, blood pressure, and self esteem, while making us fatter to protect against the next self-induced famine.

No comments: