Saturday, November 24, 2007

Another confirmation that middling weight is best

It's been a tough time the last little while for the fatties among us -- which is supposedly most of us. According to the just released report from the American Institute for Cancer Research being fat and eating certain foods increases our risk for cancer. The secret to a long life according to the report's authors is to be as thin as you can, while avoiding red meat, processed meats, alcohol, French fries, milk shakes and, well, you get the picture.

But in contrast to the cancer report, which received enormous and largely uncritical media attention, a new study about obesity by Katherine Flegal and colleagues from the Centers for Disease Control and the National Cancer Institute made few waves. Yet Flegal's quiet and careful study could do much to calm our growing national hysteria about obesity.

Flegal used data from the National Health and Nutrition Examination Survey, which is a representative sample of the US population, to find the connections between being underweight, overweight and obese and cardiovascular disease (CVD), cancer and many other causes of death. The results are startling since they confound much of the received wisdom about being fat in America.

Flegal discovered that being overweight (BMI's of 25-30) was not responsible for increased mortality. In fact for CVD, cancer and all other causes, being overweight actually increased one's chance of living longer. In total, overweight was associated with a total of 138, 281 fewer deaths. Being overweight is not likely to kill you.

She found that being obese increased the risk of premature death for the most part in only the most obese, that is those with BMI's over 35. In other words, even modest obesity is not a death sentence. For example, those with BMI's of 30-35 aged 25-69 did not have a statistically significant increased risk of dying from cardiovascular disease. Indeed, for cancer the results are even more startling since even those with BMI's in excess of 35 did not have a statistically significant increased risk of dying. And for all other diseases other than CVD and cancer, obesity up to a BMI of 35 was modestly protective -- that is, likely to result in a longer rather than a shorter life.

She also found that being underweight carries substantial risks. Whereas obesity accounts for 95, 442 deaths, being thin is associated with 46, 398 -- almost half as many deaths as obesity. But then one is unlikely to ever hear about the risks of being thin or the mortality toll associated with underweight.

Nor are these findings a fluke. In 2005 Flegal and the same team found that being overweight reduced one's chances of dying, that the majority of deaths due to obesity were in the morbidly obese, and perhaps most surprisingly, that there was no statistically significant increased risk for death associated with even modest obesity.

The implications of these findings, which barely registered in the news cycle, are significant. They suggest that most Americans need not worry about being too fat, since most mortality is associated with BMI's in excess of 35. They suggest that the continual message from the government and the public health community to lose weight or to be as thin as possible lacks a credible scientific basis. And they suggest that it is those who weigh too little whose plight also deserves some attention.


A guy who is drunk as a skunk gets aggressive and it is a a drug that he is taking (not the booze) that is to blame??

Why are tales of side-effects so often plagued by such bogus causal reasoning? You can draw NO valid causal inferences from rare episodes. Coincidence is not cause

Government scientists are investigating whether a drug from Pfizer used to help smokers quit cigarettes also increases suicidal thoughts and violent behavior. The Food and Drug Administration said on Tuesday that it had received reports of mood disorders and erratic behavior among patients taking Chantix, Pfizer’s prescription drug used to help quit smoking.

The F.D.A. said it was still gathering information about the drug, but advised doctors to closely monitor patients taking Chantix for behavior changes. Sales of the drug totaled $101 million last year. The agency said it was investigating at least one incident involving Chantix and a violent death.

Family members of a musician in Dallas, Carter Albrecht, recently said that Chantix might have caused the rage that led to his death. Mr. Albrecht was shot in the head in September by his girlfriend’s neighbor as he tried to kick down the man’s door. An autopsy report showed that Mr. Albrecht’s blood alcohol level was three times the legal limit.

The agency said it had asked Pfizer for information on additional cases that might be similar. Regulators said it was unclear if Chantix was directly responsible for the behavior, because nicotine withdrawal often aggravates existing mental problems. Pfizer, which is based in New York, also submitted reports to the agency on increased drowsiness among patients taking Chantix.



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 correla-tion 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 condi-tions and lynchings in Raper's data. Raper had the misfortune of stopping his anal-ysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic condi-tions 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.


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