Friday, March 07, 2008

Some Experts Doubt Obesity Epidemic

Go on, have another doughnut. According to some experts whose views are public health heresy, the jury is still out on how dangerous it is to be fat. "The obesity epidemic has absolutely been exaggerated," said Dr. Vincent Marks, emeritus professor of clinical biochemistry at the University of Surrey. Marks is among a minority of skeptics who doubt the severity of the obesity problem. They claim that the data about the dangers of obesity are mixed and there is little proof that being fat causes problems including high blood pressure, heart disease and cancer. Such views contradict nearly everything doctors have been saying for years.

Being fat has long been blamed for conditions like diabetes, which can lead to heart, kidney and nerve diseases. There is also increasing evidence that certain cancers may be linked to weight gain. "The evidence linking obesity to diabetes and cardiovascular disease is very strong," said Dr. James Hill, director of the Center for Human Nutrition at the University of Colorado. "Type two diabetes rarely happens in people who aren't obese."

But obesity contrarians say that there's no data proving why being fat - in itself - would be dangerous. "There's no good causal connection," said Eric Oliver, author of Fat Politics and a political science professor at the University of Chicago. Blaming obesity for diabetes and heart attacks, Oliver says, is like blaming lung cancer on bad breath rather than on smoking. Excess weight may actually be a red herring, Oliver says, since other factors like exercise, diet or genetic predispositions towards diseases are harder to measure than weight.

In addition to questioning the dangers of being fat, researchers like Marks also criticize oft-repeated alarmist projections about the rise in obesity - like the British government's warning that nearly half of Britain will be obese by 2050. Those simply aren't based on good evidence, they say. According to national health statistics released last month, from 1993 to 2006, "relatively little change" was noted in weight gain, with men and women gaining an average of about 4 kilograms (9 pounds). In children, no significant gains were recorded.

The main problem, obesity skeptics say, is that too many people are considered fat, with the obese and overweight often lumped together. "Being moderately plump is not a health disadvantage," Marks said. "Some overweight people may not look svelte, but they may be perfectly healthy." As defined by the World Health Organization, anyone with a body mass index above 25 is overweight, and anyone above 30 is obese. Most experts agree the distinctions are imperfect and somewhat arbitrary.

Moreover, Marks and others point to research showing the benefits of a few extra kilos (pounds). In 2005, Katherine Flegal of the United States' Centers for Disease Control and Prevention published a study in the Journal of the American Medical Association, finding that overweight people typically live longer than normal-weight people. More than a dozen other studies have come to the same conclusion.

Outrage ensued. Prominent health experts called the research flawed and worried that people would gleefully supersize their meals. "I think some experts found it disturbing that we actually said that overweight people have a lower death risk," Flegal said. In other research, Flegal and colleagues found there to be almost no link between death rates and weight. "The relationship between weight and disease and survival is very complex and we don't have a good handle on why some of these things are related and others are not," Flegal said. She suggested that being fat may help you survive some conditions, but not others.

Doctors have long struggled to explain the obesity paradox - the mystery that in certain conditions like heart attacks, fat patients often have better odds of surviving than thin people. Some experts hypothesize that fat peoples' hearts already work harder than those of thin people, thus giving them a natural edge when their bodies are stressed. "We don't want people to think it's ok to be heavier," said Hill. "But not everybody who gains weight is going to get heart disease or diabetes," he said.

Some obesity skeptics question the motives of experts who make dire predictions about obesity. With millions of dollars for obesity researchers, an industry of anti-fat drugs, and a boom in the number of doctors offering surgeries like stomach-stapling, the more fat people there are, the more profits there will be in selling them solutions.

Experts on both sides of the obesity debate have often criticized WHO's overweight and obesity measures, saying they are too low. When WHO defined the body mass index scores constituting normal, overweight and obese, they appeared to be the result of an independent expert committee convened by WHO. Yet the 1997 Geneva consultation was held jointly with the International Obesity Task Force, an advocacy group whose self-described mission is "to inform the world about the urgency of the (obesity) problem."

According to the task force's most recent available annual report, more than 70 percent of their funding came from Abbott Laboratories and F. Hoffman La-Roche, companies which make top-selling anti-fat pills. The task force remains one of Europe's most influential obesity advocacy groups and continues to work closely with WHO.

The blurred lines between pharmaceutical money and obesity groups have also caused concern in Britain. In 2006, one of the country's top obesity doctors quit the organization he founded to combat obesity, the National Obesity Forum, complaining that its goals had been skewed by drug money. "There's not a lot of money in trying to debunk obesity, but a huge amount in making sure it stays a big problem," said Patrick Basham, a professor of health care policy at Johns Hopkins University.

Still, while skeptics insist that obesity warnings must be taken with a grain of salt, nearly all agree that while a little bit of extra padding may not be too deadly, too much almost certainly is. "The vast majority of people who get labeled under the obesity epidemic are well under 300 pounds and probably are not facing big health consequences," Oliver said. "It's the morbidly obese people who should be worried."


Snow eating now endangered kid pleasure

To the list of simple childhood pleasures whose safety has been questioned, add this: eating snow. A recent study found that snow - even in relatively pristine spots like Montana and the Yukon - contains large amounts of bacteria. Parents who warn their kids not to eat dirty snow (especially the yellow variety) are left wondering whether to stop them from tasting the new-fallen stuff, too, because of Pseudomonas syringae, bacteria that can cause diseases in bean and tomato plants.

But experts say there's no need to banish snow-eating along with dodgeball, unchaperoned trick-or-treating and riding a bike without a helmet. "It's a very ubiquitous bacteria that's everywhere," says Dr. Penelope Dennehy, a member of the American Academy of Pediatrics' committee on infectious diseases. "Basically, none of the food we eat is sterile. We eat bacteria all the time." Children practically bathe in bacteria when they go to the playground, and Dennehy says they won't get anything from snow that they wouldn't get from dirt. "We eat stuff that's covered with bacteria all the time, and for the most part it's killed in the stomach," says Dr. Joel Forman, a member of the pediatric academy's committee on environmental health. "Your stomach is a fantastic barrier against invasive bacteria because it's a very acidic environment."

There are exceptions. "Tiny kids on formula a lot of times don't have the acid in their stomachs," making them more vulnerable to bacteria in general, says Dr. Lynnette Mazur, a professor of pediatrics at the University of Texas Medical School. Also, Forman and Mazur say that Pseudomonas can be a threat to people with cystic fibrosis.

The study, published last week in the journal Science, didn't examine the effects on people. And experts say without further information, it is impossible to say what the bacteria could do to a child who eats extraordinary amounts. "I can say that I'm not aware of any clinical reports of children becoming ill from eating snow. And I looked," Forman says.

In any case, because of ordinary air pollution in snow, it's probably wise not to eat a lot of the stuff, pediatricians say. For parents in search of guidance, Mazur offers this: Licking a little snow off a glove is probably OK. "A meal of snow" is not.

Some parents say they are not going to worry about their kids eating snow that looks clean. "My snow-eating concerns are generally more of the dirt-urine variety," says Kristin Lang, 37, of Maplewood, N.J., whose 2-year-old son Charlie has swallowed his share of snow. "When I heard bacteria, at first I went 'eew,'" says Tricia Sweeney, a mother of three in Cornwall-on-Hudson, N.Y. But as long as the kids eat snow as it's falling, "I think it's OK. I tell them not to eat it if it's on the ground."



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

9). And how odd it is that we never hear of the huge American study which showed that women who eat lots of veggies have an INCREASED risk of stomach cancer? So the official recommendation to eat five lots of veggies every day might just be creating lots of cancer for the future! It's as plausible (i.e. not very) as all the other dietary "wisdom" we read about fat etc.

10). And will "this generation of Western children be the first in history to lead shorter lives than their parents did"? This is another anti-fat scare that emanates from a much-cited editorial in a prominent medical journal that said so. Yet this editorial offered no statistical basis for its opinion -- an opinion that flies directly in the face of the available evidence.

Even statistical correlations far stronger than anything found in medical research may disappear if more data is used. A remarkable example from Sociology:
"The modern literature on hate crimes began with a remarkable 1933 book by Arthur Raper titled The Tragedy of Lynching. Raper assembled data on the number of lynchings each year in the South and on the price of an acre's yield of cotton. He calculated the correlation coefficient between the two series at -0.532. In other words, when the economy was doing well, the number of lynchings was lower.... In 2001, Donald Green, Laurence McFalls, and Jennifer Smith published a paper that demolished the alleged connection between economic conditions and lynchings in Raper's data. Raper had the misfortune of stopping his analysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic conditions deteriorated, yet lynchings continued to fall. The correlation disappeared altogether when more years of data were added."
So we must be sure to base our conclusions on ALL the data. But in medical research, data selectivity and the "overlooking" of discordant research findings is epidemic.

"What we should be doing is monitoring children from birth so we can detect any deviations from the norm at an early stage and action can be taken". Who said that? Joe Stalin? Adolf Hitler? Orwell's "Big Brother"? The Spanish Inquisition? Generalissimo Francisco Franco Bahamonde? None of those. It was Dr Colin Waine, chairman of Britain's National Obesity Forum. What a fine fellow!


1 comment:

smallylerned said...

>"There's no good causal >connection," said Eric >Oliver

I thought that, in the case of diabetes, the postulated causal chain was something like: Obesity causes insulin resistance causes type 2 diabetes.