Nieman, David C. Dr.P.H., FACSM
David C. Nieman, Dr.P.H., FACSM, is professor and director of the Human Performance Laboratory, Appalachian State University, in Boone, North Carolina; an active researcher; and author of several textbooks on health and fitness. Email your questions to firstname.lastname@example.org.
Q: ACCORDING TO MY PHYSICIAN, I'M 40 TO 50 LBS OVERWEIGHT FOR MY HEIGHT OF 65 INCHES. HE SAYS I NEED TO LOSE THIS EXCESS WEIGHT IF I INTEND TO LIVE A LONG AND HIGH-QUALITY LIFE. I'M CONFUSED ABOUT WHAT I HEAR AND READ FROM THE NEWS MEDIA REGARDING HEALTH AND OVERWEIGHT. IS EXCESS WEIGHT REALLY THAT BAD FOR YOUR HEALTH?
A: Yes, the health hazards linked with being overweight are real and of great consequence. I think the "fit and fat" discussion and debates among scientists regarding the actual number of deaths per year caused by obesity have caused some confusion among media reporters and readers. Nonetheless, the U.S. Centers for Disease Control and Prevention (CDC) now regards obesity as the second most important medical and public health problem of our era. Only smoking exceeds obesity in its contribution to early death (1).
The prevalence of overweight and obesity has increased sharply, with two in three adults now above a body mass index (BMI) of 25 kg/m2 (1). Data from two national government surveys show that, among adults aged 20 to 74 years, the prevalence of obesity (BMI exceeding 30 kg/m2) increased from 15% in the 1970s to 33% (in the 2003-2004 survey). One of the national health objectives for the year 2010 is to reduce the prevalence of obesity among adults to less than 15%. However, according to the CDC, current data indicate that the situation is worsening rather than improving. Now, compared with 1960, the average adult weighs 24 lbs more, and the average teenager weighs 15 lbs more. American male subjects currently weigh 190 lbs at a height of 69 inches, with female subjects at 163 lbs and 64 inches.
There are at least nine major health problems resulting from being overweight. Eight in ten overweight people have one of the health problems listed below, with 25% having two or more. Overweight people most vulnerable to these health problems tend to have more of their fat in the abdomen rather than the hip and thigh areas. In other words, if you are an overweight woman with a waistline exceeding 35 inches, or an overweight man pushing 40 or more inches, then the odds of having the health hazards listed below are higher than expected.
Here are the major health problems related to carrying excess body weight (2-6):
* Increased high blood pressure-high blood pressure is much more common among the overweight, and the risk climbs strongly with increases in body weight. This relationship between obesity and high blood pressure exists even among school children.
* Increased levels of cholesterol and bloodfats-overweight individuals are more likely than normal weight persons to have high blood cholesterol and triglycerides and lower high-density lipoprotein cholesterol.
* Increased heart disease and stroke-overweight people not only have more of the risk factors for heart disease and stroke but also die from these two types of cardiovascular disease at a much higher rate.
* Increased diabetes-obesity is the strongest of all lifestyle risk factors for diabetes.
* Increased cancer-obese men and women have higher cancer death rates for most of the major cancers when compared with the non obese (e.g., colon and prostate cancer in men and breast cancer in women).
* Increased osteoarthritis-overweight persons are at high risk for osteoarthritis in the knee and hips.
* Increased gallbladder disease-the risk for gallstones rises sharply with increase in body weight.
* A psychological burden-because of strong pressures from society to be thin, obese people often have feelings of guilt, depression, anxiety, and low self-esteem.
* Increased early death-death rates from all causes are higher among the obese. The lowest death rates have been linked to a body weight 10% to 20% below the American average.
There are many other obesity-related health problems that do not affect large numbers of people but are significant nonetheless. For example, obesity has been related to mental health problems; sleep apnea; increased lost workdays because of illness, injury, or disability; decreased willingness to see a physician for cancer screening; higher risk of erectile dysfunction and sexual dysfunction; early puberty; aberrant menstrual patterns; decreased contraceptive efficacy; and increased miscarriage rate (7,8).
The good news is that disease risk factors are quickly brought under control when you lose just 10% or more of your body weight. For example, if you weigh 200 lbs and lose 20 lbs (as a first step goal), most of the health risks will show measurable improvement. The secret to long-term weight management is "caloric awareness" or the ability to tightly balance the calories ingested versus those expended (Figure). The challenge is combating the pressures within the American society to eat high amounts of food and be physically inactive.
Figure. Surgeon Gene...Image Tools
As I teach my students, if you value your health, the most important lifestyle goal next to avoidance of cigarette smoking is keeping thin and active all your life. Not only will you feel better, life expectancy is typically 6 to 15 years longer in thin, physically active, nonsmokers.
1. Flegal, K.M., B.I. Graubard, D.F. Williamson, et al. Cause-specific excess deaths associated with underweight, overweight, and obesity. Journal of the American Medical Association
2. Giovannucci, E., and D. Michaud. The role of obesity and related metabolic disturbances in cancers of the colon, prostate, and pancreas. Gastroenterology
3. Zhang, C., K.M. Rexrode, R.M. van Dam, et al. Abdominal obesity and the risk of all-cause, cardiovascular, and cancer mortality: sixteen years of follow-up in US women. Circulation
4. Renehan, A.G., D.L. Roberts, C. Dive. Obesity and cancer: pathophysiological and biological mechanisms. Archives of Physiology and Biochemistry
5. Pearson-Ceol, J. Literature review on the effects of obesity on knee osteoarthritis. Orthopedic Nursing
6. Orsini, N., R. Bellocco, M. Bottai, et al. Combined effects of obesity and physical activity in predicting mortality among men. Journal of Internal Medicine
2008 May 29 [Epub ahead of print].
7. Ostbye, T., J.M. Dement, and K.M. Krause. Obesity and workers' compensation: results from the Duke Health and Safety Surveillance System. Archives of Internal Medicine
8. Lash, M.M., and A. Armstrong. Impact of obesity on women's health. Fertility and Sterility
2008 Apr 12 [Epub ahead of print].
9. U.S. Department of Health and Human Services. The Surgeon General's call to action to prevent and decrease overweight and obesity. Rockville: U.S. Department of Health and Human Services, Public Health Service, Office of the Surgeon General, 2001. Available at www.surgeongeneral.gov/library