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By DrRich

Dateline: October 14, 2002

According to a report in the October 9 issue of the Journal of the American Medical Association, the prevalence of obesity in the U. S. population continues to increase at an alarming rate. In this report, the authors describe the results of a survey conducted in 1999 and 2000 among 4115 men and women as part of the National Health and Nutrition Examination Survey, and compare these results to those of a similar survey conducted from 1988 to 1994.

Their results are startling. In 1999-2000, 64.5% of Americans were found to be overweight, and 30.5% were obese. Extreme obesity was found in 4.7% These results represent a significant increase in obesity and overweight just over the past few years.  (In the earlier survey, a "mere" 55.9% of adults were overweight, 22.9% were obese, and 2.7% were extremely obese.)

These increases in obesity were seen in all demographic groups: in men and women, in all age groups, and in whites, African Americans, and Hispanics.  The increases in obesity reported in this study represent a continuation of a disturbing trend that began in the late 1970s or early 1980s.

How fat is fat?

Being overweight has significant medical consequences (see below), and the more overweight you are, the greater the consequences.  In fact, the definition of "overweight" used in these studies is based on the weight at which increased medical risk begins to occur.  Weight-related medical risk is tied to a quantity called Body Mass Index (BMI), which is a function of an individual's weight and your height.  Overweight is defined as a BMI of at least 25.  Obese is a BMI of at least 30.  And extreme obesity is a BMI of at least 40.  If your BMI is 25 or greater, your medical risk is higher than it should be.

Estimating your own BMI

As noted, the BMI is a function of your weight and your height.  Click here for a web site, maintained by the CDC, that gives your estimated BMI when you enter your height and weight. 

Consequences of being overweight

The health consequences of being overweight are many, and they are serious.  Here is a partial list of medical conditions that are particularly common in overweight individuals.  The risk of developing these medical conditions increases substantially once your BMI is 25 or greater, but the higher your BMI the higher the risk:

• hypertension
• coronary artery disease
• heart attacks
• heart failure
• type II diabetes
• stroke
• gallstones
• gout
• osteoarthritis
• sleep apnea
• some types of cancer (such as breast, endometrial, prostate, and colon)

Most of these conditions are chronic, debilitating - and expensive.  The rapid fattening (and the rapid aging) of our population, health economists are beginning to realize, is destined to add substantially to the already-dire financial condition of our health care system.

Causes of the increase in obesity

On the face of it, there is a simple explanation for why people gain weight.  The ONLY cause of weight gain is to eat more calories than you burn up during your daily activities.  For approximately every 3600 "extra" calories you take in, you gain one pound.  It's that simple. 

But why is our entire society becoming fat?  And why now, and why so rapidly?  There is no single answer to these questions.

One thing we can conclude with some certainty is that it isn't just our genes - it's what we're doing (or not doing). While it appears that, at least in some individuals, there is a genetic predisposition to obesity, genes clearly do not explain the rapid increase in obesity we are now seeing in our population.  After all, Americans have not had a sudden change in their genetic makeup over the last 20 years.  The only logical explanation for this rapid fattening of America is in our lifestyles, and in what we are eating.  And these two factors have changed recently.

Americans are less active than they once were.  Automation, computers, satellite TV and video games are ever more prevalent, and unless we make a specific effort to exercise, it is all too easy for many of us to live completely sedentary lives.  Apparently, we are.

Also, there is no doubt that the American diet isn't what it once was. We are eating more highly processed foods, and more fast foods, most of which are loaded with sugars, fats, and a new culprit - trans-fatty acids. (Click here for a description of trans-fatty acids and the problems they cause.)

In any case, it is now impossible to avoid the conclusion that the American lifestyle and the American diet are unhealthful.

What you can do about your weight

There are only two ways to reduce your weight: increase your activity, or decrease your caloric intake.  Either method implies a change in lifestyle; hence the difficulty most people have in losing weight and keeping it off.

Example: A typical 12 ounce can of soda contains 150 calories.  By reducing your consumption by a single can of pop every day, you can lose 10 pounds in a year.  Conversely, by drinking a can of pop a day you can gain 10 pounds in a year. Another way to lose 150 calories a day would be to take a daily brisk 30 minute walk.

Most people who lose weight and keep it off find that they have to make a conscious commitment to a new lifestyle, one that includes more physical activity and a balanced diet. Unless a lot more people make these tough choices, there won't be enough healthy working people around in another 20 years to provide the taxes necessary to buy health care for the rest of us.

Coming soon from DrRich: What is so fattening about the American diet - too much fat, or too many carbohydrates?

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