TCS Daily


By Sandy Szwarc - August 4, 2003 12:00 AM

If being overweight is as deadly as we've been told, the evidence should be irrefutable. It's not.


"The conclusion that obesity is dangerous represents a selective review of the data," concluded David Garner, Ph.D., and Susan Wooley, Ph.D., in "Confronting the Failure of Behavioral and Dietary Treatments for Obesity," published by Clinical Psychology Review in 1991.


The Truth About Obesity
The Skinny on Fat
The Diet Problem
Dying to Be Thin
The War on Fat's Casualties
To Your Health
Where's the Epidemic?
To Do List
A Simple Plan
Mikey Doesn't Like It

Their comprehensive examination of studies on obesity-related mortalities and morbidities found  repeated design problems, cases where the key conclusions contradicted the data and summaries that selectively chose studies supporting the conclusions of the researchers. Challenging the popular view of obesity-linked mortalities, they said, "a number of epidemiological studies and reviews have concluded either that obesity does not confer elevated health risks or that such risks have been greatly exaggerated."


That's the same conclusion Glenn Gaesser, Ph.D. arrived at after scrutinizing all the relevant data in his book, Big Fat Lies: The Truth About Your Weight and Your Health (Fawcett Columbine, 1996).


"Those beliefs [that obesity is dangerous] are so firmly entrenched in our fat-phobic mindset that they are seldom questioned," Gaesser, an associate professor of exercise physiology at the University of Virginia, wrote. "But they should be. The idea that a given body weight, or a percentage of body fat, is a meaningful indicator of health, fitness, or prospects for longevity is ... one of our most dubious propositions."


In their detailed review of epidemiological studies published in 1987 in the Journal of Obesity and Weight Regulation, researchers Paul Ernsberger, Ph.D., and Paul Haskew, Ed.D., often found no reliable association between premature death and relative weight, as measured by the Body Mass Index (BMI). "Across lifespan, the net impact of BMI is minimal,"  Ernsberger, an associate professor of Medicine, Pharmacology and Neuroscience, Case Western Reserve School of Medicine, said.


"The majority of investigations have shown that weighing 20 to 50 pounds over chart recommendations is associated with little, if any, increased risk of early death," Dr. Steven Blair, president of the Cooper Institute in Dallas, said.



Thin Support for Fat Guidelines


Repeated long-term studies and reviews of existing studies in the Journal of the American Medical Association (JAMA) and the Archives of Internal Medicine have tried in vain to prove overweight a risk factor for premature death.


In fact, the vast majority of studies find weight to be irrelevant to health and mortality, or that being overweight or obese actually appears to be healthier, offering the best prospects for long life. As Gaesser wrote, "The 'definitive proof' that being thinner means living longer turns out to be dwarfed in comparison to a vast, globe-encircling body of evidence based on data that has been collected since the 1950s on hundreds of thousands of men and women of different ages, races, nationalities and ethnicities."


One of the most comprehensive analyses of the relationship between body weight and mortality ever published was done by researchers at the Centers for Disease Control and Prevention (CDC) National Center for Health Statistics and Cornell University in 1996. Studying data on more than 600,000 men and women for 30 years, they found the lowest mortality for men was at BMIs 23 to 29, mostly weights considered overweight (by up to 50 pounds!) under current guidelines. They also found the highest mortality in BMIs under 23, comparable only to those who were the most extremely overweight. It was riskier to be slim than moderately obese. In women, a wider range of BMIs was perfectly healthy and mortality rates didn't begin to rise until BMIs reached 32 and beyond.


Another study on women, led by Kevin Fontaine, Ph.D., of John Hopkins University, concurred that a broad range of weights were well-tolerated, and found mortality risks were actually lowest at a BMI around 34.


Given the largest body of scientific evidence suggests we'll live the longest with some extra meat (or fat) on our bones, and it's actually more dangerous to be slender, the government's new National Heart, Lung, and Blood Institute (NHLBI) Guidelines, defining overweight as being BMIs of 25 to 29.9 and obesity at BMIs of 30 or higher, make little sense. Those distinctions are controversial because they imply health risks which aren't supported by research, according to Frances Berg, M.S., editor-in-chief of Healthy Weight Journal.


Being fat isn't unhealthy?


Fat has been blamed for just about every health problem imaginable. The evidence indicates those few of us at the most extreme end of obesity do begin to see greater health risks, but those risks do not translate to the majority of us who are overweight to moderately obese. "What evidence exists for an association between obesity and mortality or morbidity, is usually found not to apply to those with mild to moderate obesity," Garner and Wooley said.


Although we're told that weighing anything over "ideal" is unhealthy, overweight has "never been tied to objective assessments of body fat as a causal factor in either higher disease or higher mortality rates," said Gaesser. There is no association between being overweight and rates of diabetes, gallstones, high blood pressure, high cholesterol, colon cancer, heart disease, stroke, and other health problems.


That's goes against everything that's been drilled into us for decades. Since heart disease is the biggest killer, let's look at its evidence in more detail. 


A 1989 JAMA review of almost 100 studies found fatness is not a risk factor for atherosclerosis or coronary heart disease. Also, although rarely mentioned, when cardiovascular health risks are found, they also don't necessarily translate into higher mortality rates.


Ancel Keys, Ph.D.,  researcher of 16 long-term studies in seven countries, concluded about them: "[I]n none ... was overweight or obesity a major risk factor for death or the incidence of coronary heart disease." And in actual autopsy analyses of coronary arteries by 23 medical experts in the large-scale, 14-country, International Atherosclerosis Project during the 1950s and 1960s, no link was found between body weight or body fat and vessel disease. Five decades of subsequent autopsy studies have also concluded obesity does not cause heart disease.


Plumpness not merely benign, but good


Good news about fatness is almost never uttered, as if it might excuse what our thin-obsessed culture views as objectionable. But there's actually a considerable amount of positive findings. In addition to longer life spans, fat people have lower rates of most cancers, respiratory diseases, and osteoporosis.


Cancers are where the benefits are especially notable, according to Gaesser, who has counted about 40 studies in the past 30 years indicating lower cancer rates and mortality among fat people. According to the National Research Council, obesity appears to protect against overall cancer deaths and against deaths from the specific cancers that are the leading causes of cancer death, such as premenopausal breast, lung, stomach and colon cancer in women, and lung and stomach cancer in men.


"Moderate obesity may also be protective during illness," Ernsberger added. "You are much more likely to survive a hospitalization if you are over ideal weight."


The strongest scientific evidence indicates we'll live longest and with the fewest health problems if we're in the overweight range, especially as we get older. Older people who are average or moderately overweight have four times less risk of dying prematurely than those who are underweight or lose weight. The 1998 Panel Study of Income Dynamics found the lowest health risks among mature women were at much higher BMIs than current guidelines, so women might be best advised to welcome middle-aged spread.


Gaining weight is natural as we age. The 1994 Mayo Foundation for Medical Education and Research study found men and women to be 15 and 19.5 percent fat respectively at 18 years of age, but 25 and 32 percent by age 56. With age, fat cells become less metabolically active, so weight gain can be healthy, Wayne Callaway, M.D., of George Washington University, said.


Reubin Andres, M.D., a gerontologist at the National Institute on Aging and a professor of medicine at Johns Hopkins, found that the fewest deaths occurred in those whose weights increased as they aged. "It's acceptable, possibly even highly beneficial, for normal, healthy adults to gain gradually about a pound a year beginning around age 40, so that by the time they're in their 60s they weigh about 20 pounds more than the Met Life tables would suggest," he said in Food & Nutrition Digest (Extension Foods and Nutrition, Cooperative Extension Service, Kansas State University, March/April 1995).


What's your ideal weight?


Weights deemed "ideal" set body fat standards at 15 percent for men and 22 percent for women, which excludes 75 to 90 percent of American adults, Gaesser noted. Yet the total body of research shows no clear picture of what's an ideal weight, he said: "Ideal for one isn't the same for another. Obesity can be a natural and normal state for some, not a disease."


"Let's face biological reality," Dr. Blair said. "Some people are naturally meant to be thin, some naturally meant to be fat. ... I don't like the term 'ideal weight.' I don't think we know what any person's ideal weight is. Human beings come in different sizes and shapes. On any characteristic you care to name, there's tremendous variation, from eye color to hair color, for those who have hair and those who don't have hair, and we vary. Some of us are short and stocky. Some are tall and skinny. So to claim that some formula can produce a so-called 'ideal weight' that we can then apply to an individual I think is faulty logic."


Ideal weight is not a medical standard, but a societal preference. Our cultural "ideal" weight continues to shrink, unrelated to healthfulness. "It's possible to be healthy at any size," concurred Phillip Walker, M.S., director of Walker Wellness Clinic in Dallas.


In fact, "you can be obese and quite healthy," believes Rudolph Leibel, M.D., director of the division of molecular genetics at Columbia University College of Physicians and Surgeons.


Your healthiest weight might not be what's considered "ideal" at all, said Carol A. Johnson, M.A., president of Largely Positive and author of Self Esteem Comes in All Sizes (Gurze Books, 2001). Plenty of women want to diet to meet societal ideals, when they're already at the healthiest weight for their bodies.


Like many clinicians, Frances Berg, M.S., defines a healthy weight as the weight the body naturally adopts when eating well and living actively. You're healthy in terms of blood pressure, heart disease measurements, glucose tolerance, etc. A healthy weight is different for each of us and our bodies resist trying to force them into something radically different from their set point.


Forget dieting to reach some goal weight


For overweight people in good health, there's no scientific evidence to show that they'll be better off if they lose weight, according to Gaesser.


Just because someone looks fat, doesn't mean they're not healthy. In a 2001 issue of Metabolism, obesity expert Ethan Sims, M.D., emeritus professor at medicine at the University of Vermont, noted that  it's important to identify the healthy subgroup "to avoid blame and inappropriate treatments, [and] in research to avoid confounding statistical analysis."


Weight loss may be indicated, according to the NIH, for those severely overweight or obese people experiencing "health problems that can be lessened by weight loss such as sleep apnea, hypertension and type II diabetes." Even that is controversial, though, and many believe there are healthier ways to overcome most "weight-related" health problems.


If dieting is chosen, there is abundant clinical research to show that there's no benefit in trying to achieve "ideal" body weights. Slowly losing as little as 5 percent body weight reduces or eliminates disorders associated with obesity, according to many experts, including George Blackburn, M.D., Ph.D., of the Center for the Study of Nutrition and Medicine at Harvard Medical School. For example, at-risk people can reduce their risk of diabetes by 58 percent, Ernsberger said.


"Actually, very little weight loss is necessary to resolve weight-associated health problems," Gaesser points out. "You'll see 90 percent of health benefits in the first 5 pounds; problem is most people want to lose weight to look better not be healthier."


On Wednesday: We'll discover the secret to being healthy and the most powerful predictor of an early death.


© 2003 Sandy Szwarc. All rights reserved.


TCS Daily Archives