TCS Daily


The Diet Problem

By Sandy Szwarc - July 18, 2003 12:00 AM

Looking back 40 or more years, the movie stars and bathing beauties we admired were healthy full-figured gals with plenty of jiggle and cellulite. The nation didn't have a "weight problem." The difference between then and now is that "diet" wasn't in our vocabulary and being thin wasn't a cultural obsession.

But as dieting has become increasingly more widespread in America, body weights have increased, the January/February 1999 issue of Healthy Weight Journal, after an extensive examination of the evidence surrounding dieting, reported.

In fact, dieting is a predictor of fatness. Among girls who diet their risk for obesity is 3.24 times greater than for nondieters. Dieting among adults is similarly associated with an increased risk of long-term weight gain, according to studies by Allison Daee, R.D., and colleagues at the University of Missouri.

The Truth About Obesity
07/14/2003
The Skinny on Fat
07/16/2003
The Diet Problem
07/18/2003
Dying to Be Thin
07/22/2003
The War on Fat's Casualties
07/24/2003
To Your Health
07/28/2003
Where's the Epidemic?
07/30/2003
Ideal-isms
08/04/2003
To Do List
08/06/2003
A Simple Plan
08/08/2003
Mikey Doesn't Like It
08/06/2003
An overwhelming body of research has demonstrated the link between dieting and obesity. The problem is that evidence flies in the face of the reigning orthodoxy in the current battle of the bulge, which cannot afford to acknowledge that the decisive consequence of dieting is ... obesity.

In their comprehensive scientific review of the efficacy of dietary treatments for obesity, entitled "Confronting the Failure of Behavioral and Dietary Treatments for Obesity," published by Clinical Psychology Review in 1991, researchers David Garner, Ph.D., and Susan Wooley, Ph.D., concluded that there is "overwhelming evidence from controlled studies that weight loss programs are ineffective in producing lasting weight change."

"Unfortunately," Garner, currently director of River Centre Clinic in Sylvania, Ohio, and adjunct professor at Bowling Green State University and the University of Toledo, said "[our findings] are still accurate despite over 10 more years of research since the Review was written."

Regardless of the weight-loss method used -- special diets (no matter what they advocate), fasting, pills or surgery -- there's an initial short-term weight loss that deems the treatment a success. But looking further, failures are strikingly consistent and more remarkable the longer follow-up is continued. According to a plethora of studies, such as F.M. Kramer's long-term follow-up study published in a 1989 International Journal of Obesity, less than 1 to 3 percent of weight loss is ever maintained over the long run. By four or five years out, almost all dieters have regained all or most of their weight, and most will weigh more than they did at the start of their diets.

The larger and more rapid the weight loss, the more profound and rapid the weight regain, according to research headed by Albert Stunkard, M.D., professor of psychiatry at the University of Pennsylvania School of Medicine and founder of the Weight and Eating Disorders Program. His teams' findings concur with multiple other studies which have found that the greater the weight loss, the higher the follow-up weight -- meaning patients end up considerably more obese after dieting. "It is only the rate of weight regain, not the fact of weight gain, that appears open to debate," Garner and Wooley noted.

That explains why the heavier a person is the more likely he or she is to have dieted. "The prevalence of dieting increases with BMI," said Glenn Gaesser, Ph.D., associate professor of exercise physiology at the University of Virginia and a Fellow of the American College of Sports Medicine (ACSM). And dramatically so. "Among those with BMIs under 25, 25 percent have dieted, while those with BMIs above 30, at least 60 to 70 percent have dieted."

If diets did what they promised -- and increasingly more of us want to believe they can -- those who've dieted would be joining the ranks of those at lower BMIs as living proof that diets worked. Instead, former dieters grow increasingly more prevalent among those at higher BMIs, and they're getting continually fatter, as they try all the more fervently again and again to lose weight.

Clearly, as anyone struggling with their weight will tell you, "Diets don't work."

Dieting Builds Fat

The concept that we're literally dieting our way to obesity is easy to grasp. Most of us just haven't thought about it that way before. Our bodies are designed to adapt to stress -- it's critical for survival. Consider the body builder who wants to build muscle: he'll stress his muscles with training to tear them down, knowing his body will build them back up bigger. Some people will never become muscle-bound no matter how hard they lift weights -- it's not in their genes or physiological make-up. Others become Arnold Schwarzenegger look-alikes without barely trying.

That same physiological response for muscle tissue works with fat. Dieting is precisely fat-building. We stress our body by dieting and make it think it's nearing starvation, forcing it to break down fat to supply the energy we need for survival. Afterwards, as soon as the body's given any nourishment above starvation levels, it biologically reacts by putting on more fat, holding onto fat more vehemently, and conserving more of what we eat thereafter as fat.

What's happened? We've trained our bodies to expect another starvation period, sometimes permanently. This is normal. Without it, mankind would not have survived countless periods of famine. In fact, some scientists believe those whose bodies don't react this way have the genetic aberration. Humans are genetically designed to defend against weight loss much more so than to defend against weight gain, notes Dr. Miina Ohman at the Departments of Molecular Medicine and Medical Genetics at the University of Helsinki, Finland.

How can diets do all that? Diets appear to change a number of biological processes, and trigger fat-storing mechanisms, that are outside the dieter's control. Dieting does so especially intensely among those dieters genetically designed for survival during lean times. So, those with weight problems are not only most likely to diet, but also to suffer from the most detrimental physiological changes brought on by dieting.

Multiple researchers have found that weight loss with dieting is at the expense of muscle mass and vital organs such as brain, heart, kidney and liver. In Clinical Nutrition and Dietetics (Prentice Hall, 1990), Frances Zeman, Ph.D., R.D., documented that skeletal muscle protein is broken down for energy at about 0.8 pound lean tissue per day during the first five to seven days of a low-calorie diet, and drops to a rate of about a quarter pound per day thereafter. The body then holds onto fat and eventually breaks it down at a much lower rate of 0.4 pound per day. Thus, up to 45 percent of weight loss from dieting comes not from losing fat but from the body cannibalizing its own muscle tissue, according to experts in Exercise and Sport Science Reviews (Academic Press, 1975).

Worst of all, our diet-triggered survival propensities mean that weight then regained after dieting is preferentially as fat. Studies have shown it's largely gained as visceral fat around our organs and in the upper torso, which is associated with the greatest risk for heart disease, high blood pressure and type II diabetes. After dieting, especially repeated dieting, formerly fat people may look and weigh the same as naturally lean folks, but have high percentages of body fat -- technically they're still obese!

Dieting completely alters fat metabolism, not just by changing the percentage and composition of body fat. As we've seen, it also hampers our ability to lose it again, and it raises insulin levels. (Insulin is the fat-building hormone, encouraging fat storage and resisting fat break down. High insulin levels prelude high blood pressure, abnormal blood cholesterol levels and atherosclerosis.) Dieting also appears to deplete our body's reserves of healthy omega-3 fatty acids, Gaesser has noted.

All of these may help explain the multitude of studies demonstrating the increased risks for heart disease, cancers and death from dieting. These dangers "may be more significant than generally acknowledged," Gaesser said.

"It's a common misperception that fat is a choice and that fat people could lose weight if they wanted to," Gaesser added. "It's not true."

Obesity: Not a Lifestyle 'Choice'

Genes aside, the inability to achieve the purported ideal body weight, is not the fault of a dieter's lack of will power or character, but the failure of dieting and other weight loss methods themselves, concluded experts at the 1992 National Institutes of Health (NIH) conference on weight loss.

Numerous studies have consistently demonstrated more than just impressive changes in our fat metabolism, but that weight loss results in a 15 to 30 percent reduction in energy requirements. That means, body weight can only be maintained by eating increasingly less food. In a 1988 animal study published in Physiology and Behavior, dieting triggered as much as a four-fold increase in metabolic (i.e. fuel) efficiency.

Even short-term calorie restrictions and small changes in weight result in dramatic metabolic changes. For example, a study by George Bray, M.D., in Lancet found that a mere 3 percent weight loss in obese patients lowered resting metabolic rates 17 percent. Researchers at the University of Missouri found that dieting reduced metabolic rates to the point that fat people have to increasingly eat fewer calories to lose weight or they can actually gain weight on diets.

And this doesn't stop at the end of a diet. According to Drs. Jerome Knittle and David Katz of Mount Sinai School of Medicine in Total Nutrition (St. Martin's Griffin, 1995), after dieting the lowered metabolism often doesn't return to its former level, so that with normal food intake the post-dieter quickly gains weight even more quickly than before. They documented studies finding people unable to eat more than 800 to 900 calories a day -- starvation levels, according to the World Health Organization -- after dieting, without gaining weight.

A 1996 review of the National Weight Control Registry of successful long-term weight losers found that in order to maintain weight loss these people had to eat near semi-starvation levels, even though most were also exercising religiously. The average woman was eating 1,297 calories a day and the average man 1,725 calories, almost half of what would be considered normal for good health.

Carol A. Johnson, M.A., a research sociologist and certified therapist specializing in issues of size and weight, and president of Largely Positive, said, "Scientists are only now beginning to understand the complex physiological processes that influence a person's weight."

Obesity's Other 'Environmental Toxins'

What's been discovered to date concerning the causes of obesity leaves little doubt that it's much more complicated than it appears and considerable more research is needed. Most researchers, including Rudolph Leibel, M.D., at Rockefeller Hospital, have concluded obesity is biological, not psychological, or due to sloth or gluttony alone. Future research may end up taking us down roads we haven't yet even considered.

Similar changes in body metabolism, from inhibited fat burning to enhanced conversion of sugar into stored fat, are also seen with higher levels of the stress hormone cortisol. It's produced by our adrenal glands during times of stress, fatigue and lack of sleep. Many researchers have found those suffering from stress and fatigue gain weight more easily, especially abdominal visceral fat that's been linked to greater risks of heart disease and diabetes. Heightened stress, fatigue and lack of sleep are certainly prevalent in our society -- the stress to be thin included.

Obesity has also been clinically linked with physiological and psychological trauma, according to Jack Wilmore, Ph.D., of Texas A&M University, in the President's Council on Physical Fitness and Sports Research Digest: "Hormonal imbalances, emotional trauma, and alterations in basic homeostatic mechanisms have all been shown to be directly or indirectly related to the onset of obesity."

And to throw out yet another possible contributor to obesity in some people that has yet to be researched: viruses. A study by researchers at the University of Wisconsin in Madison, in the August 2000 International Journal of Obesity, found animals infected with adenovirus were slightly heavier, but almost twice as fat, as healthy animals.

The Diet Cure Hoax

As researchers try to figure out why some of us get fat and others don't, it's increasingly apparent that obesity appears to be different conditions, caused by a vast array of linked genes, hormones and other physiological changes, and environmental influences. With no single cause, it therefore has no single "cure," according to the FDA.

This, and what we've already learned, calls into question the entire treatment of obesity advocated to date: dieting. The 1992 NIH conference review of weight loss stated, "The paucity of well-designed, long-term clinical trials evaluating various methods for voluntary weight loss is disturbing."

According to Garner and Wooley, "It is difficult to find any scientific justification for the continued use of dietary treatments of obesity."

Even if obesity is a problem, many researchers question the concept that dieting or weight loss is the cure. Changing how someone looks on the outside will not change what's going on in the inside, nor will it change whatever health risk factors may be linked to his or her genes.

Yet, obesity is the only condition we look to treat simply by changing appearances without addressing the physiological or genetic factors inside. Imagine treating Tay-Sachs, a genetic disease primarily among Jews of Eastern European descent, by forcing patients to change their religion. Or, Sickle cell disease, found among peoples of African descent, by dying their skin. Such suggestions would be considered not only bad science, but also demeaning, if not prejudicial.

So, why do we deal with weight issues in such unscientific, biased manners, especially when there are much safer and more effective ways?

As Gaesser has noted, there is no proven benefit of weight loss for otherwise healthy people. "The 'lose weight-live longer' paradigm is not well supported," he has argued, and with a less than 1 to 3 percent success rate the "long-term efficacy of dieting-induced weight loss is certainly not well established."

Ideally, before public health policy measures are instituted, their benefits need to be proven -- the benefits must clearly outweigh the risks. Perhaps the government should follow its own advice. The Federal Trade Commission (FTC) has brought action against some commercial weight loss programs, challenging their weight loss and maintenance claims.

The FDA describes health fraud as "articles of unproven effectiveness that are promoted to improve health, well being or appearance." That would appear to define nearly all the weight loss measures that have been proposed.

Coming Tuesday: The dark side of the war on obesity that is costing Americans their livelihoods and their lives.

© 2003 Sandy Szwarc. All rights reserved.
Categories:
|

TCS Daily Archives