Why what we think about eating is so often wrong
May 8, 2015
By Peter Whoriskey
Here’s how public thinking on food gets shaped: Every year, researchers publish hundreds of academic studies about the health effects of various foods – chocolate, kale, red wine, anything. Those studies, in turn, become fodder for newspaper articles, books and blog posts.
But how much of this torrent of information is worth the trouble? Surprising little, according to a number of key researchers.
In recent years, these skeptics have caused a stir by poking big holes in the nutritional science behind popular diet advice. Even the findings published in distinguished health journals have come under fire.
Collectively, their work suggests that we know far less than we think we do about what to eat.
“Is everything we eat associated with cancer?” a much noted paper in this vein asked.
Published in the American Journal of Clinical Nutrition, the paper reviewed the academic studies conducted on common cookbook ingredients. Of the 50 ingredients considered, 40 had been studied for their impact on cancer. Individually, most of those studies found that consumption of the food was correlated with cancer. When the research on any given ingredient was considered collectively, however, those effects typically shrank or disappeared.
“Many single studies highlight implausibly large effects, even though evidence is weak,” the authors concluded.
Indeed, much of the field appears to be beset with doubt. And now comes the controversies sparked by the U.S. Dietary Guidelines – the governmental diet recommendations that are being updated this year. In February, we learned that the government is poised to withdraw its longstanding warning about consuming foods that are rich in cholesterol. At the same time, the government’s advice on salt, saturated fats and other foods are under attack, too. The ongoing back-and-forth over these foods tends to buttress the skeptics’ argument that public health authorities have too often issued nutrition advice before the science was settled.
With the public comment period on the Dietary Guidelines ending this week, it seemed like a good time to connect with David B. Allison, of the University of Alabama-Birmingham, one of the leading skeptics. In recent years, Allison and his colleagues have taken aim at an array of frequently dispensed nuggets of nutrition advice — for example, that eating fruits and vegetables aids in weight loss or that skipping breakfast might cause weight gain.
More generally, Allison and others have pointed to problems in the way that nutrition research is conducted, criticizing everything from the way that food intake is measured, which is often imprecise and deeply flawed, to the inferences that scientists draw from their findings.
In conversation, Allison was exceptionally stinting in his diet advice – unwilling to stray much beyond the fact that we need food to live, and that if we eat too much we get fat.
One final note: The professor’s skepticism applies to nutritional claims made by the government as well as to those made by the food industry, and in fact, Allison and the university has received funding from both, as his disclosures show.
Nutrition science seems to be undergoing an enormous state of flux. Officials are poised to drop their longstanding warning about cholesterol in foods; the evidence for the government’s warning about salt has shifted; and scientists are still arguing over what kinds of fats are good and bad for you.
Is this normal?
Yes and no.
All scientific knowledge is provisional. That is accepted. We learn.
On the other hand, the extent to which we are changing in nutrition now seems greater than it is in some other fields, and much of what we once considered rock solid science being called into question.
[Given all this change], there are people wondering, “Hey guys, could we just hold on a second?”
We’ve put a man on the moon. We’ve mapped black holes and distant galaxies. Why is it so hard to figure out what we should eat?
There are many reasons.
For one, there is a presupposition that eating some things is better than eating other things. But is it? It’s like ESP – some people might ask ‘Why can’t you find good evidence of ESP?’ Maybe it’s because there is no ESP.
Another reason is it’s really difficult to do the kinds of experiments we’d like.
When we start to talk about how long do you live on this diet, or whether you get a cancer or stroke, that is not so easy to study in humans. You need large numbers of people to eat what you tell them for a very long period of time. Typically, you want thousands of people over a period of years. You can immediately see that if you can get them to do it at all, could you even afford to do the study? Those kinds of studies are very rare.
You’ve written about how scientists themselves distort what is known, mainly by making the evidence they have seem stronger than it really is. For example, you counted up instances in which researchers wrote that skipping breakfast “caused” weight gain, when in fact their study merely showed that skipping breakfast is associated with weight gain.
What are the motives here?
There’s more than one. One is innocent. Some people just didn’t think it through. That’s not an excuse – it’s still sloppy bad science.
Others may be well-meaning but they think they generally already know what is good and bad. They want to do as much as possible to convince everyone that what they think is ‘good’ is actually good and what they think is ‘bad’ is bad.
A third factor is a kind of moral passion or indignation.
Given, all of these ways that the science can go wrong, what do we actually know about what’s good for us?
There are a few things we are certain about. We know that you can’t live without food, and that if you eat too much, you get fat. There are certain essential nutrients – vitamins and minerals – that you need to have. You should make sure there is no lead or mercury or other toxins in your food.
After that the knowledge base gets thinner and thinner.
Maybe you shouldn’t have a diet that is extremely high in saturated fat or trans fats or sugars. Do we know this beyond any reasonable doubt? No. But we know enough to say this could be considered a prudent diet.
But that’s the way we need to tell people. We need to say, ‘We think,’ not ‘We know.’ We need to be careful about is not pretending we know more than we really do.
The Politics Of Obesity: Seven Steps To Government Action
Concern is rapidly growing about obesity rates in the United States. This paper analyzes the political consequences. Despite myths about individualism and self-reliance, the U.S. government has a long tradition of regulating ostensibly private behavior. We draw on the historical experience in four other private realms (alcohol, illegal drugs, tobacco, and sexuality) to identify seven “triggers” that prompt government to intervene in citizens’ private habits. We suggest which of those triggers have been tripped?or are in play?in the case of obesity and food consumption. Finally, we review what government now does in this field and what it might do in the future.
Obesity May Be Wired In The Brain, Rat Study Suggests
ScienceDaily (Feb. 6, 2008) ? A predisposition for obesity might be wired into the brain from the start, suggests a new study of rats.
Rats selectively bred to be prone to obesity show abnormalities in a part of the brain critical for appetite control, the researchers found. Specifically, the researchers show that the obese rats harbor defects in neurons of the arcuate nucleus (ARH) of the hypothalamus, which leaves their brains less responsive to the hunger-suppressing hormone leptin.
“The neurodevelopmental differences in these animals can be seen as early as the first week,” said Sebastien Bouret of the University of Southern California. “The results show that obesity can be wired into the brain from early life. The three-million-dollar question now is how to get around this problem.”
It is increasingly accepted that obesity results from a combination of genetic and environmental factors, the researchers said. Rodent models of obesity can provide valuable insights into the biological processes underlying the development of obesity in humans. The “diet-induced obese” (DIO) rats used in the current study are particularly suited to the task, according to Bouret, because their tendency to become overweight shares several features with human obesity, including the contribution of many genes.
Previous studies had suggested that the brains of DIO rats are insensitive to leptin, the researchers added. Circulating leptin, produced by fat tissue, acts as a signal to the brain about the body’s energy status. Leptin is also critical for the initial development of ARH neurons.
In the new study, the researchers examined the obesity-prone rats for signs of abnormal brain development. They found that the animals’ brains had fewer neural projections from the ARH, a deficiency that persisted into adulthood. Those projections are needed to relay the leptin signal received by the ARH to other parts of the hypothalamus, Bouret said.
The researchers found further evidence that those changes in brain wiring stem from a reduced responsiveness of the brain to leptin’s action during development.
“It seems [in the case of these rats] that appetite and obesity are built into the brain,” Bouret said. While their condition might be ameliorated by exercising and eating right, he added, the findings suggest that the propensity to gain weight can’t be reversed.
But there is hope yet. It’s possible that treatments delivered during a critical early period of development might be capable of rewiring the brain, Bouret said.
This research was published in the February issue of Cell Metabolism, a publication of Cell Press.
The researchers include Sebastien G. Bouret, Neuroscience Program, The Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA, Inserm, U837, Jean-Pierre Aubert Research Center, Universite´ Lille, Lille, France; Judith N. Gorski, Neurology Service, Veterans Affairs Medical Center, East Orange, NJ, Department of Neurology and Neurosciences, New Jersey Medical School, Newark, NJ, Department of Pharmacology, Merck Research Laboratories, Rahway, NJ; Christa M. Patterson, Neurology Service, Veterans Affairs Medical Center, East Orange, NJ, Department of Neurology and Neurosciences, New Jersey Medical School, Newark, NJ; Stephen Chen, Neuroscience Program, The Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA; Barry E. Levin, Neurology Service, Veterans Affairs Medical Center, East Orange, NJ, Department of Neurology and Neurosciences, New Jersey Medical School, Newark, NJ; and Richard B. Simerly, Neuroscience Program, The Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California, Los Angeles, CA.
Adapted from materials provided by Cell Press, via EurekAlert!, a service of AAAS.
Study: Obese people, smokers cheaper to treat
Long-living healthy people medically more expensive in long run
February 05, 2008
? A Dutch study compared the health-care costs of three groups: thin and nonsmoking, obese people and smokers.
? Cancer incidence, except for lung cancer, was the same in all three groups. Obese people had the most diabetes, and healthy people had the most strokes.
? Ultimately, the thin and healthy group cost the most, about $417,000, from age 20 on. The cost of care for obese people was $371,000, and for smokers, about $326,000.
? The results counter the common perception that preventing obesity will save health systems worldwide millions of dollars.
? The study did not take into account other potential costs of obesity and smoking, such as lost economic productivity or social costs.
Treating obesity and smoking is cheaper than keeping folks fit, study says
Feb. 4, 2008
LONDON – Preventing obesity and smoking can save lives, but it doesn’t save money, researchers reported Monday.
It costs more to care for healthy people who live years longer, according to a Dutch study that counters the common perception that preventing obesity would save governments millions of dollars.
“It was a small surprise,” said Pieter van Baal, an economist at the Netherlands’ National Institute for Public Health and the Environment, who led the study. “But it also makes sense. If you live longer, then you cost the health system more.”
In a paper published online Monday in the Public Library of Science Medicine journal, Dutch researchers found that the health costs of thin and healthy people in adulthood are more expensive than those of either fat people or smokers.
Van Baal and colleagues created a model to simulate lifetime health costs for three groups of 1,000 people: the “healthy-living” group (thin and non-smoking), obese people, and smokers. The model relied on “cost of illness” data and disease prevalence in the Netherlands in 2003.
The researchers found that from age 20 to 56, obese people racked up the most expensive health costs. But because both the smokers and the obese people died sooner than the healthy group, it cost less to treat them in the long run.
On average, healthy people lived 84 years. Smokers lived about 77 years, and obese people lived about 80 years. Smokers and obese people tended to have more heart disease than the healthy people.
Cancer incidence, except for lung cancer, was the same in all three groups. Obese people had the most diabetes, and healthy people had the most strokes. Ultimately, the thin and healthy group cost the most, about $417,000, from age 20 on.
The cost of care for obese people was $371,000, and for smokers, about $326,000.
The results counter the common perception that preventing obesity will save health systems worldwide millions of dollars.
“This throws a bucket of cold water onto the idea that obesity is going to cost trillions of dollars,” said Patrick Basham, a professor of health politics at Johns Hopkins University who was unconnected to the study. He said that government projections about obesity costs are frequently based on guesswork, political agendas, and changing science.
“If we’re going to worry about the future of obesity, we should stop worrying about its financial impact,” he said.
Obesity experts said that fighting the epidemic is about more than just saving money.
“The benefits of obesity prevention may not be seen immediately in terms of cost savings in tomorrow’s budget, but there are long-term gains,” said Neville Rigby, spokesman for the International Association for the Study of Obesity. “These are often immeasurable when it comes to people living longer and healthier lives.”
Van Baal described the paper as “a book-keeping exercise,” and said that governments should recognize that successful smoking and obesity prevention programs mean that people will have a higher chance of dying of something more expensive later in life.
“Lung cancer is a cheap disease to treat because people don’t survive very long,” van Baal said. “But if they are old enough to get Alzheimer’s one day, they may survive longer and cost more.”
The study, paid for by the Dutch Ministry of Health, Welfare and Sports, did not take into account other potential costs of obesity and smoking, such as lost economic productivity or social costs.
“We are not recommending that governments stop trying to prevent obesity,” van Baal said. “But they should do it for the right reasons.”
In the Fatosphere, Big Is In, or at Least Accepted
By RONI CARYN RABIN
January 22, 2008
For years, health experts have been warning that Americans are too fat, that we exercise too little and eat too much, that our health is in jeopardy.
Some fat people beg to differ.
Blogs written by fat people ? and it’s fine to use the word, they say ? have multiplied in recent months, filling a virtual soapbox known as the fatosphere, where bloggers calling for fat acceptance challenge just about everything conventional medical wisdom has to say about obesity.
Smart, sassy and irreverent, bloggers with names like Big Fat Deal, FatChicksRule and Fatgrrl (“Now with 50 percent more fat!”) buck anti-obesity sentiment. They celebrate their full figures and call on readers to accept their bodies, quit dieting and get on with life.
The message from the fatosphere is not just that big is beautiful. Many of the bloggers dismiss the “obesity epidemic” as hysteria. They argue that Americans are not that much larger than they used to be and that being fat in and of itself is not necessarily bad for you.
And they reject a core belief that many Americans, including overweight ones, hold dear: that all a fat person needs to do to be thin is exercise more and eat less.
“One of the first obstacles to fat acceptance is breaking down the question of whether being fat is a choice,” Kate Harding, founder of the blog Shapely Prose, said in an interview. “No fat acceptance advocate is saying you should sit around and wildly overeat. What we’re saying is that exercise and a balanced diet do not make everyone thin.”
Ms. Harding, a 33-year-old yoga enthusiast from Chicago, promotes the idea of health at any size (she is a 16). She started Shapely Prose (kateharding.net) last April, after noticing that posts about fat in her personal blog hit a nerve. Since then, it has quickly become one of the most popular fat acceptance blogs, with an average of 3,710 page views per day, according to Sitemeter, a Web statistics program.
People come in different shapes and sizes, bloggers like Ms. Harding say, and for those who come extra-large, dieting is futile. Many of the bloggers label their sites “no-diet zones.” (Don’t even mention weight-loss surgery.)
“You relapse, and then you go on a diet again, and this time you’re going to do it, it’s really going to be it this time,” Marianne Kirby, a 30-year-old blogger from Orlando, Fla., who writes The Rotund (therotund.com), said in an interview. “And it still doesn’t work, not long-term ? you end up heavier than before. And you say to yourself: Why did I fall for this again?’ “
The blogs have drawn their share of negative, even vicious comments. But for overweight readers, the messages are empowering ? and liberating.
“Girlfriend, let me tell you, I am finally coming to grips with myself,” one fan commented on Ms. Harding’s site. “I will always be fat. I accept that now.”
Harriet Brown, a 49-year-old blogger in Wisconsin and an occasional contributor to The New York Times, encourages readers to take her “I Love My Body Pledge” (at harrietbrown.com), in which they promise not to talk “trash” about “how fat my thighs or stomach” are, and not “call myself a fat pig.”
Fat Fu’s anonymous blog (fatfu.wordpress.com) has a ruthless deconstruction of recent research like the “fat friends” study, as well as one of the most comprehensive lists of links to the fatosphere, including online communities, fashions and health sites for fat people. The Big Fat Deal blog (bfdblog.com) suggests 10 ways to be a “body positivity activist,” including “Be yourself,” “Understand that a lot of people are hateful morons” and “Don’t be afraid to order the cheesecake.”
Many of the bloggers are women whose writing has a distinctly feminist flavor, but there are male fat-acceptance bloggers like Red No. 3 (red3.blogspot.com), who says: “See, I don’t have a problem with fat. My body is simply adorned, and I’ll take that.”
But some experts say this sort of message is dangerous and undermines public health efforts to rein in obesity. “We do have to be careful not to put all the blame on the individual,” said Dr. Walter C. Willett, professor of nutrition and epidemiology at the Harvard School of Public Health. But he added, “The large majority of people who are overweight are overweight because of lifestyle.”
The bloggers argue that changes in definitions over time, along with flaws in the body mass index formula, have pushed more Americans into the “fat” and “obese” categories, and they point to provocative studies suggesting that there may be benefits to being overweight, including a large study that found that underweight Americans are more likely to die than those who are moderately overweight.
Several other recent studies on heart patients and dialysis patients have also reported higher survival rates among heavier patients, suggesting that the link between body size and health may be more complex than generally acknowledged. Another study of people over 60 found that being fit has more bearing on longevity than simply being thin.
The bloggers’ main contention is that being fat is not a result of moral failure or a character flaw, or of gluttony, sloth or a lack of willpower. Diets often boomerang, they say; indeed, numerous long-term studies have found that even though dieters are often able to lose weight in the short term, they almost always regain the lost pounds over the next few years.
Ultimately, these bloggers argue, being skinny may have far more to do with the luck of the genetic draw than with lifestyle choices.
“We accept that some people are tall and some people are short,” said Rachel Richardson, 28, of Cincinnati, who writes a blog called The F-Word (the-f-word.org). “Yet we seem to think all people should be thin ? it just doesn’t make sense.”
Fat acceptance bloggers contend that the war on obesity has given people an excuse to wage war on fat people and that health concerns ? coupled with the belief that fat people have only themselves to blame for being fat ? are being used to justify discrimination that would not be tolerated toward just about any other group of people.
“I’m not surprised there are so many of these blogs now,” Ms. Richardson said. “Anti-obesity hysteria has reached a boiling point. Blogging is a way for people to fight back.”
By Larry Brian Radka
The so-called “educated elite,” who frown on the smoking solace of poor working-class people, have led the attack on smokers and their holy rights. Their ardent followers are dumb ex-smokers, obese ex-smokers now, who no longer participate in God’s holy activity. Those pea-brained ex-smokers, fat hypocrites staggering along in a herd of aimless animals, can think of nothing now to do with their restless hands and mouths. So they constantly grab and gulp down fatty foods as they swell up like bloated corpses. Eventually their diabetes-ridden carcasses are trucked to hospitals. Yet, after being unloaded among snickering attendants, those dumb overgrown elephants still have the ignorant audacity to roll over in their broken-down beds and point their greasy nicotine-stained fingers at visiting smokers.
By Avram Goldstein
By Jacqueline S. Homan
© Copyright 2007 The Smoker’s Club, Inc. Please repost with link back to this original article.
Obesity is contagious.
July 22, 2007
If you’re the type who gets motivated to change by hearing scary statistics, then here’s a doozy: experts predict that if Americans continue gaining weight at the current rate, by the year 2015 (that’s only 8 years from now!) 75 percent of us will be overweight or obese.
That’s not only a majority, but a major majority. Every group in society (kids, adolescents, adults) is steadily gaining weight, and considering that 66 percent of adults were overweight or obese in 2004, I guess it’s not really a big stretch that we’ll hit 75 percent by 2015. How depressing!
Study predicts 75 percent overweight in U.S. by 2015
WASHINGTON (Reuters) – If people keep gaining weight at the current rate, fat will be the norm by 2015, with 75 percent of U.S. adults overweight and 41 percent obese, U.S. researchers predicted on Wednesday.
July 11, 2007
Contact William Hathaway at email@example.com
The Cold Sharp Slap Of Reality