The Medical Minute: Obesity is growing problem

December 12, 2006

By John Messmer
Penn State Family and Community Medicine
Penn State Milton S. Hershey Medical Center
Penn State College of Medicine

With office parties, holiday cookies, eggnog, and all the other goodies available at this time of year, who wants to read about obesity? Maybe the increase in obesity from about 27 percent of men to more than 31 percent between 2000 and 2004 is not alarming, but how about the increasing prevalence in children from 14 percent to 17 percent during the same time? Compare that to the prevalence of childhood obesity in the 60's -- about 4.5 percent.

Obesity is defined as a body mass index (BMI) over 30. Calculate BMI by multiplying body weight in pounds by 703 and divide it by the square of height in inches, or go to http://nhlbisupport.com/bmi/bmicalc.htm and plug in height and weight to have it calculated. A BMI between 25 and 30 is overweight.

Why the concern? It's not just an issue of appearance. Obesity has significant health risks associated with it. Type 2 diabetes is much more likely in obese individuals, although it can develop if one is simply overweight. Even with a normal or slightly elevated BMI, men whose waist is more than 40 inches and women with a waist size above 35 inches are at increased risk for obesity related diseases.

It turns out that fat does not just sit there. A big abdomen signifies metabolically active fat inside and out. Abdominal fat makes us more susceptible to diabetes if we have the genetics for it. It can affect cholesterol levels and increases the risk of atherosclerosis or hardening of the arteries. The kind of fat people get around their middles also deposits around our abdominal organs and can clog the liver. The so-called "fatty liver" can lead to liver damage from non-alcoholic steatohepatitis (NASH). Extra weight can increase blood pressure and make sleep apnea more likely and contributes to arthritis of weight-bearing joints and an increased chance of some cancers.

What's to be done about the problem? There is no single answer, unfortunately. For some people, it's a matter of eating too much; for others, it's too many high-calorie foods rather than quantity. Some people eat fine most of the time, but overeat once or twice a week without cutting back at other times. Holiday time is typical of this. Eating three regular meals a day plus holiday treats will add pounds.

The other problem is overestimating calories burned by exercise and underestimating the calories in foods. People burn about 350 calories an hour walking or doing moderate yard work and 700 calories an hour running or by heavy lifting and carrying. A single three-inch cookie is between 100 and 200 calories; a cup of eggnog is 350 calories; cakes and pies can be as much as 500 calories a slice depending on type. Too often people gain weight because they think walking the dog will burn off the 1,000 extra calories consumed.

Most people don't realize that we need fewer calories for the same body weight as they age. Every decade people require 10 percent fewer calories to maintain the same weight. If people do not cut back by 10 percent, they will gain that proportion of their weight over a decade.

Yes, some people seem to be "naturally" thin. Those who stay thin tend to stop eating when they have had enough, even if being served foods they really like. The genetics are still being worked out, but some experts think most people are programmed to consume and store calories when food is plentiful as a reserve in case of food scarcity. That was useful for the early settlers, but in 21st-century America, most of people have enough food, including more useless and unnecessary foods, than ever before.

People must be honest with themselves if they expect to manage their weight. The idea of having to lose a certain number of pounds can be intimidating. Plus, "going on a diet" implies that one will go "off" the diet eventually. Proper eating should be a lifetime habit, not something done for a couple months as a New Year's resolution.

Snacks, treats, junk food and the like are supposed to be an occasional thing, few and far between. Even the amount of wholesome foods people eat should be controlled. Smaller portions, particularly at restaurants, can help. Don't supersize orders. Share an entree or take a portion home for the next day. Don't skip meals -- that can lead to overeating later or can make people very efficient at storing calories so it becomes even harder to cut down. Pack a lunch for work or bring a cooler to avoid fast food runs.

Be consistent and willing to eat significantly less of unnecessary foods -- or skip them entirely. Remember that exercise helps, but it takes 90 minutes of walking on the treadmill to burn off a large order of fries and another 90 for a large fast-food sandwich.

With attention to good choices, reasonable quantity and consistency from week to week, anyone can achieve and maintain a healthy weight without feeling deprived.

(Media Contacts)

Last Updated March 19, 2009