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Higher levels of female obesity correlated with higher levels of gender inequality in each nation Of course, that’s not the impression you will get from the admonishments of public-health agencies and wellness businesses.

Yet the scientists who study the biochemistry of fat and the epidemiologists who track weight trends are not nearly as unanimous as Bloomberg makes out. In fact, many researchers believe that personal gluttony and laziness cannot be the entire explanation for humanity’s global weight gain.

Consider, for example, this troublesome fact, reported in 2010 by the biostatistician David B Allison and his co-authors at the University of Alabama in Birmingham: over the past 20 years or more, as the American people were getting fatter, so were America’s marmosets.

‘Virtually in every population of animals we looked at, that met our criteria, there was the same upward trend,’ he told me.

It isn’t hard to imagine that people who are eating more themselves are giving more to their spoiled pets, or leaving sweeter, fattier garbage for street cats and rodents. But such results don’t explain why the weight gain is also occurring in species that human beings don’t pamper, such as animals in labs, whose diets are strictly controlled. In fact, lab animals’ lives are so precisely watched and measured that the researchers can rule out accidental human influence

In rich nations, obesity is more prevalent in people with less money, education and status. Even in some poor countries, according to a survey published last year in the International Journal of Obesity, increases in weight over time have been concentrated among the least well-off. And the extra weight is unevenly distributed among the sexes, too.

The story might go like this: being poor is stressful, and stress makes you eat, and the cheapest food available is the stuff with a lot of ‘empty calories’, therefore poorer people are fatter than the better-off. These wheels-within-wheels are required because the mantra of the thermodynamic model is that ‘a calorie is a calorie is a calorie’: who you are and what you eat are irrelevant to whether you will add fat to your frame. The badness of a ‘bad’ food such as a Cheeto is that it makes calorie intake easier than it would be with broccoli or an apple.

More importantly, ‘things that alter the body’s fat metabolism’ is a much wider category than food. Sleeplessness and stress, for instance, have been linked to disturbances in the effects of leptin, the hormone that tells the brain that the body has had enough to eat.

If some or all of these factors are indeed contributing to the worldwide fattening trend, then the thermodynamic model is wrong.

According to Frederick vom Saal, professor of biological sciences at the University of Missouri, an organic compound called bisphenol-A (or BPA) that is used in many household plastics has the property of altering fat regulation in lab animals.

BPA has been used so widely — in everything from children’s sippy cups to the aluminium in fizzy drink cans — that almost all residents of developed nations have traces of it in their pee. This is not to say that BPA is unique.

Contrary to its popular image of serene imperturbability, a developing foetus is in fact acutely sensitive to the environment into which it will be born, and a key source of information about that environment is the nutrition it gets via the umbilical cord.

It’s possible that widespread electrification is promoting obesity by making humans eat at night, when our ancestors were asleep

consider the increased control civilisation gives people over the temperature of their surroundings.

Temperatures above and below the neutral zone have been shown to cause both humans and animals to burn fat, and hotter conditions also have an indirect effect: they make people eat less.

A study by Laura Fonken and colleagues at the Ohio State University in Columbus, published in 2010 in the Proceedings of the National Academy of Sciences, reported that mice exposed to extra light (experiencing either no dark at all or a sort of semidarkness instead of total night) put on nearly 50 per cent more weight than mice fed the same diet who lived on a normal night-day cycle of alternating light and dark.

A virus called Ad-36, known for causing eye and respiratory infections in people, also has the curious property of causing weight gain in chickens, rats, mice and monkeys.

xperiments by Lee Kaplan and colleagues at Massachusetts General Hospital in Boston earlier this year found that bacteria from mice that have lost weight will, when placed in other mice, apparently cause those mice to lose weight, too.

It might be that every one of the ‘roads less travelled’ contributes to global obesity; it might be that some do in some places and not in others. The openness of the issue makes it clear that obesity isn’t a simple school physics experiment.

In a capitalistic quest for new markets and cheap materials and labour, Europeans take control of the economy in the late 18th or early 19th century. With taxes, fees and sometimes violent repression, their new system strongly ‘encourages’ the farmer and his neighbours to stop growing their own food and start cultivating some more marketable commodity instead – coffee for export, perhaps. Now that they aren’t growing food, the farmers must buy it. But since everyone is out to maximise profit, those who purchase the coffee crop strive to pay as little as possible, and so the farmers go hungry. Years later, when the farmer’s children go to work in factories, they confront the same logic: they too are paid as little as possible for their labour. By changing the farming system, capitalism first removes traditional protections against starvation, and then pushes many previously self-sufficient people into an economic niche where they aren't paid enough to eat well.

Eighty years later, the farmer’s descendants have risen out of the ranks of the poor and joined the fast-growing ranks of the world’s 21st-century middle-class consumers, thanks to globalisation and outsourcing. Capitalism welcomes them: these descendants are now prime targets to live the obesogenic life (the chemicals, the stress, the air conditioning, the elevators-instead-of-stairs) and to buy the kinds of foods and beverages that are ‘metabolic disturbers’.

Wells memorably calls this double-bind the ‘metabolic ghetto’, and you can’t escape it just by turning poor people into middle-class consumers: that turn to prosperity is precisely what triggers the trap.

The ‘unifying logic of capitalism’, Wells continues, requires that food companies seek immediate profit and long-term success, and their optimal strategy for that involves encouraging people to choose foods that are most profitable to produce and sell — ‘both at the behavioural level, through advertising, price manipulations and restriction of choice, and at the physiological level through the enhancement of addictive properties of foods’ (by which he means those sugars and fats that make ‘metabolic disturber’ foods so habit-forming).

One possible response, of course, is to decide that no obesity policy is possible, because ‘science is undecided’. But this is a moron’s answer: science is never completely decided; it is always in a state of change and self-questioning, and it offers no final answers. There is never a moment in science when all doubts are gone and all questions settled,

Faced with signs of a massive public-health crisis in the making, governments are right to seek to do something, using the best information that science can render, in the full knowledge that science will have different information to offer in 10 or 20 years.

Influential food writers, advocates, and celebrity restaurant owners are repeating the mantra that "sustainable food" in the future must be organic, local, and slow. But guess what: Rural Africa already has such a system, and it doesn't work. Few smallholder farmers in Africa use any synthetic chemicals, so their food is de facto organic. High transportation costs force them to purchase and sell almost all of their food locally. And food preparation is painfully slow. The result is nothing to celebrate: average income levels of only $1 a day and a one-in-three chance of being malnourished.

It's true that the story of the Green Revolution is not everywhere a happy one. When powerful new farming technologies are introduced into deeply unjust rural social systems, the poor tend to lose out.

Foreign assistance to support agricultural improvements has a strong record of success, when undertaken with purpose. In the 1960s, international assistance from the Rockefeller Foundation, the Ford Foundation, and donor governments led by the United States made Asia's original Green Revolution possible.

Development skeptics and farm modernization critics keep pushing us toward this unappealing second path. It's time for leaders with vision and political courage to push back.

it’s hard not to note that cancer and heart disease are primarily diseases of aging, and life expectancy was so much lower back in the day that a much smaller percentage of the population lived to advanced ages than is the case today.

Over the last decade, Cordain has become the most prominent promoter of the so-called “Paleo diet,” having written The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat and multiple other books advocating a paleolithic-mimetic diet as the cure for what ails modern humans.

But how does one determine what the prevalence of cardiovascular disease was in the ancient past?

there have been indications that the idea that ancient humans didn’t suffer from atherosclerosis is a comforting myth, the most recent of which is a study published a week ago online in The Lancet by Prof. Randall C. Thompson of Saint Luke’s Mid America Heart Institute and an international team of investigators entitled Atherosclerosis across 4000 years of human history: the Horus study of four ancient populations.

So, although there was a fair amount of evidence from studies of Egyptian mummies that atherosclerosis was not uncommon, in Egypt it was mainly the wealthy and powerful who were mummified after their deaths. Conceivably, they could have lived a very different lifestyle and consumed a very different diet than the average Egyptian living around that time.

So the authors obtained whole-body CT scans of the 137 mummies, either pre-existing scans or scans prospectively done, and analyzed them for calcifications.

Figure 2 summarizes the findings nicely: There’s also this video featured in a Nature report on the study showing the reconstructed scan of one of the mummies with atherosclerotic plaques in the coronary arteries.

As expected, more atherosclerosis correlates with advanced age, and the amount of atherosclerosis in the young and middle-aged (although the times in which the people who became these mummies after death lived age 50 was old) was less.

As is noted in Thompson’s article, ancient Egyptians and Peruvians were agricultural cultures with farms and domesticated animals, Ancestral Puebloans were forager-farmers, and the Unangans were hunter-gatherers without agriculture. Indeed, the Peruvians and Ancestral Puebloans predated the written word and were thus prehistoric cultures.

One notes that no one, including the authors of this study, is saying that lifestyle and diet are not important factors for the development of atherosclerotic heart disease.

I actually think that the authors probably went too far with that last statement in that, while they might be correct that atherosclerosis is an inherent component of human aging, it is quite well established that this inherent component of aging can at least be worsened by sedentary lifestyle and probably certain diets.

One notes that, although the Paleo Diet is not, strictly speaking, always sold as CAM/IM, the ideas behind it are popular among CAM advocates, and the diet is frequently included as part of “integrative medicine,” for example, here at the University of Connecticut website, where it’s under integrative nutrition.

In particular, the appeal to ancient wisdom and ancient civilizations as yet untouched by the evil of modernity is the same sort of arguments that are made in favor of various CAM modalities ranging from herbalism to vegan diets rebranded as being somehow CAM to the appeal to “natural” cures.

The book is by Marlene Zuk and entitled Paleofantasy: What Evolution Really Tells Us About Sex, Diet, and How We Live. Zuk is an evolutionary biologist, and in particular she points out how the evolutionary arguments favored by advocates of the Paleo diet don’t stand up to scrutiny.

The interview begins with Zuk confronting Cordain at a conference on evolution and diseases of modern environments. At his lecture, Cordain pronounced several foods to be the cause of fatal conditions in people carrying certain genes.

Blue eyes arose 6,000 to 10,000 years ago

Rapid selection for the CCR5-D gene variant that makes some people immune to HIV

Lactase persistence (production past the age of weening of the lactase enzyme that digests lactose in milk) probably dates back only around 7,500 to 10,000 years, around the time that cattle were domesticated

Zuk detects an unspoken, barely formed assumption that humanity essentially stopped evolving in the Stone Age and that our bodies are “stuck” in a state that was perfectly adapted to survive in the paleolithic environment. Sometimes you hear that the intervention of “culture” has halted the process of natural selection. This, “Paleofantasy” points out, flies in the face of facts. Living things are always and continuously in the process of adapting to the changing conditions of their environment, and the emergence of lactase persistence indicates that culture (in this case, the practice of keeping livestock for meat and hides) simply becomes another one of those conditions.

For this reason, generalizations about the typical hunter-gatherer lifestyle are spurious; it doesn’t exist. With respect to what people ate (especially how much meat), the only safe assumption was “whatever they could get,” something that to this day varies greatly depending on where they live. Recently, researchers discovered evidence that people in Europe were grinding and cooking grain (a paleo-diet bugaboo) as far back as 30,000 years ago, even if they weren’t actually cultivating it. “A strong body of evidence,” Zuk writes, “points to many changes in our genome since humans spread across the planet and developed agriculture, making it difficult at best to point to a single way of eating to which we were, and remain, best suited.”

Oh, and, as Zuk tells us, paleolithic people got cancer, too.

we humans have long been known to abuse and despoil our environment, even back in those “paleo” days. Indeed, when I took a prehistoric archeology course, which was largely dedicated to the period of time of the hunter-gatherers, one thing I remember my professor pointing out, and that was that what he did was largely the study of prehistoric garbage and that humans have always produced a lot of it.

Violations of the USDA's organic labeling rules can earn companies civil penalties of up to $11,000. If that seems small, it should. The low penalties and the volume of organic products flooding the markets have led to skepticism that the USDA is properly enforcing the label, inspecting foods, and punishing violators. Some worry that "organic" has turned into a marketing term with little meaning. Still, when you buy organic goods at most stores and from most known brands, you can be largely sure that it meets the guidelines.

Granted, the latest study is far from the last word on nutritional value and organic foods, but it's important to note that nutritional value is neither in the stated mission of the USDA's organic food certification program (and, from what we can tell, not in that of other countries either).

A sharp eye would note that this could be because organic yields tend to be lower and there are fewer organic farms in general.

The study had two things to say about contamination: that conventionally farmed meat and produce were more likely to be contaminated with antibiotic-resistant bacteria, but both had equal risk of being contaminated overall.

Maybe sometimes it’s the questions that are biased, not the answers,” he said, flashing a friendly smile.

That question has been central to Ioannidis’s career. He’s what’s known as a meta-researcher, and he’s become one of the world’s foremost experts on the credibility of medical research.

He charges that as much as 90 percent of the published medical information that doctors rely on is flawed.

“I take all the researchers who visit me here, and almost every single one of them asks the tree the same question,” Ioannidis tells me, as we contemplate the tree the day after the team’s meeting. “‘Will my research grant be approved?’” He chuckles, but Ioannidis (pronounced yo-NEE-dees) tends to laugh not so much in mirth as to soften the sting of his attack. And sure enough, he goes on to suggest that an obsession with winning funding has gone a long way toward weakening the reliability of medical research.

“I assumed that everything we physicians did was basically right, but now I was going to help verify it,” he says. “All we’d have to do was systematically review the evidence, trust what it told us, and then everything would be perfect.” It didn’t turn out that way. In poring over medical journals, he was struck by how many findings of all types were refuted by later findings. Of course, medical-science “never minds” are hardly secret. And they sometimes make headlines, as when in recent years large studies or growing consensuses of researchers concluded that mammograms, colonoscopies, and PSA tests are far less useful cancer-detection tools than we had been told; or when widely prescribed antidepressants such as Prozac, Zoloft, and Paxil were revealed to be no more effective than a placebo for most cases of depression; or when we learned that staying out of the sun entirely can actually increase cancer risks; or when we were told that the advice to drink lots of water during intense exercise was potentially fatal; or when, last April, we were informed that taking fish oil, exercising, and doing puzzles doesn’t really help fend off Alzheimer’s disease, as long claimed. Peer-reviewed studies have come to opposite conclusions on whether using cell phones can cause brain cancer, whether sleeping more than eight hours a night is healthful or dangerous, whether taking aspirin every day is more likely to save your life or cut it short, and whether routine angioplasty works better than pills to unclog heart arteries.

“I realized even our gold-standard research had a lot of problems,” he says.

This array suggested a bigger, underlying dysfunction, and Ioannidis thought he knew what it was. “The studies were biased,” he says. “Sometimes they were overtly biased. Sometimes it was difficult to see the bias, but it was there.” Researchers headed into their studies wanting certain results—and, lo and behold, they were getting them. We think of the scientific process as being objective, rigorous, and even ruthless in separating out what is true from what we merely wish to be true, but in fact it’s easy to manipulate results, even unintentionally or unconsciously. “At every step in the process, there is room to distort results, a way to make a stronger claim or to select what is going to be concluded,” says Ioannidis. “There is an intellectual conflict of interest that pressures researchers to find whatever it is that is most likely to get them funded.”

He chose to publish one paper, fittingly, in the online journal PLoS Medicine, which is committed to running any methodologically sound article without regard to how “interesting” the results may be. In the paper, Ioannidis laid out a detailed mathematical proof that, assuming modest levels of researcher bias, typically imperfect research techniques, and the well-known tendency to focus on exciting rather than highly plausible theories, researchers will come up with wrong findings most of the time.

The article spelled out his belief that researchers were frequently manipulating data analyses, chasing career-advancing findings rather than good science, and even using the peer-review process—in which journals ask researchers to help decide which studies to publish—to suppress opposing views.

Ioannidis was putting his contentions to the test not against run-of-the-mill research, or even merely well-accepted research, but against the absolute tip of the research pyramid. Of the 49 articles, 45 claimed to have uncovered effective interventions. Thirty-four of these claims had been retested, and 14 of these, or 41 percent, had been convincingly shown to be wrong or significantly exaggerated. If between a third and a half of the most acclaimed research in medicine was proving untrustworthy, the scope and impact of the problem were undeniable. That article was published in the Journal of the American Medical Association.

When a five-year study of 10,000 people finds that those who take more vitamin X are less likely to get cancer Y, you’d think you have pretty good reason to take more vitamin X, and physicians routinely pass these recommendations on to patients. But these studies often sharply conflict with one another. Studies have gone back and forth on the cancer-preventing powers of vitamins A, D, and E; on the heart-health benefits of eating fat and carbs; and even on the question of whether being overweight is more likely to extend or shorten your life. How should we choose among these dueling, high-profile nutritional findings? Ioannidis suggests a simple approach: ignore them all.

the odds are that in any large database of many nutritional and health factors, there will be a few apparent connections that are in fact merely flukes, not real health effects—it’s a bit like combing through long, random strings of letters and claiming there’s an important message in any words that happen to turn up.

nd these problems are aside from ubiquitous measurement errors (for example, people habitually misreport their diets in studies), routine misanalysis (researchers rely on complex software capable of juggling results in ways they don’t always understand), and the less common, but serious, problem of outright fraud (which has been revealed, in confidential surveys, to be much more widespread than scientists like to acknowledge).

And so it goes for all medical studies, he says. Indeed, nutritional studies aren’t the worst. Drug studies have the added corruptive force of financial conflict of interest. The exciting links between genes and various diseases and traits that are relentlessly hyped in the press for heralding miraculous around-the-corner treatments for everything from colon cancer to schizophrenia have in the past proved so vulnerable to error and distortion, Ioannidis has found, that in some cases you’d have done about as well by throwing darts at a chart of the genome.

Though scientists and science journalists are constantly talking up the value of the peer-review process, researchers admit among themselves that biased, erroneous, and even blatantly fraudulent studies easily slip through it.

Of those 45 super-cited studies that Ioannidis focused on, 11 had never been retested. Perhaps worse, Ioannidis found that even when a research error is outed, it typically persists for years or even decades. He looked at three prominent health studies from the 1980s and 1990s that were each later soundly refuted, and discovered that researchers continued to cite the original results as correct more often than as flawed—in one case for at least 12 years after the results were discredited.

Medical research is not especially plagued with wrongness. Other meta-research experts have confirmed that similar issues distort research in all fields of science, from physics to economics (where the highly regarded economists J. Bradford DeLong and Kevin Lang once showed how a remarkably consistent paucity of strong evidence in published economics studies made it unlikely that any of them were right).

Ioannidis initially thought the community might come out fighting. Instead, it seemed relieved, as if it had been guiltily waiting for someone to blow the whistle, and eager to hear more. David Gorski, a surgeon and researcher at Detroit’s Barbara Ann Karmanos Cancer Institute, noted in his prominent medical blog that when he presented Ioannidis’s paper on highly cited research at a professional meeting, “not a single one of my surgical colleagues was the least bit surprised or disturbed by its findings.” Ioannidis offers a theory for the relatively calm reception. “I think that people didn’t feel I was only trying to provoke them, because I showed that it was a community problem, instead of pointing fingers at individual examples of bad research,” he says. In a sense, he gave scientists an opportunity to cluck about the wrongness without having to acknowledge that they themselves succumb to it—it was something everyone else did.

The irony of his having achieved this sort of success by accusing the medical-research community of chasing after success is not lost on him, and he notes that it ought to raise the question of whether he himself might be pumping up his findings.

Tatsioni doesn’t so much fear that someone will carve out the man’s healthy appendix. Rather, she’s concerned that, like many patients, he’ll end up with prescriptions for multiple drugs that will do little to help him, and may well harm him. “Usually what happens is that the doctor will ask for a suite of biochemical tests—liver fat, pancreas function, and so on,” she tells me. “The tests could turn up something, but they’re probably irrelevant. Just having a good talk with the patient and getting a close history is much more likely to tell me what’s wrong.” Of course, the doctors have all been trained to order these tests, she notes, and doing so is a lot quicker than a long bedside chat. They’re also trained to ply the patient with whatever drugs might help whack any errant test numbers back into line.

patients often don’t even like it when they’re taken off their drugs, she explains; they find their prescriptions reassuring.

Already feeling that they’re fighting to keep patients from turning to alternative medical treatments such as homeopathy, or misdiagnosing themselves on the Internet, or simply neglecting medical treatment altogether, many researchers and physicians aren’t eager to provide even more reason to be skeptical of what doctors do—not to mention how public disenchantment with medicine could affect research funding.

being wrong in science is fine, and even necessary

When it comes to the confidence we have in our beliefs — what can be expressed in terms of probability — we can’t just make up any number we want. There’s only one consistent way to handle those degrees in beliefs.

In the strictest sense, of course, this requires a bit of mathematical knowledge. But Greenberg says there’s still an easy way to use this principle in daily life — and one that can be converted to plain English.

“It’s important to note that the idea here is not to answer the question in a precise way — like saying that it’s 3.2 times more likely — rather, it’s to get a rough sense. Is it a high number, a modest number, or a small number?”

“Much of the time people will automatically try to shoot down evidence, but you can get evidence for things that are not true. Just because you have evidence doesn’t mean you should change your mind. But it does mean that you should change your degree of belief.”

Greenberg also describes Representativeness Heuristic in which people tend to look at how similar things are.

Greenberg also says that we should shy away from phrases like, “I believe,” or “I don’t believe.” “That’s the wrong way to frame it,” he says. “We should think about things in terms of how probable they are. You almost never have anything close to perfect certainty.”

“Let’s say you believe that your nutrition supplement works,” he told us, “Then you get a small amount of evidence against it working, and you completely write that evidence off because you say, ‘well, I still believe it works because it’s just a small amount of evidence.’ But then you get more evidence that it doesn’t work. If you were an ideal reasoner, you’d see that accumulation of evidence, and every time you get that evidence, you should believe less and less that the nutritional supplements are actually working.” Eventually, says Greenberg, you end up tipping things so that you no longer believe. But instead, we end up never changing our mind.

Lastly, he also says that probabilities can depend on the observer — what is a kind of probability relativity. We all have access to different information, so different people should assign different rates of probability to different things based on different sets of evidence.

New studies also are finding that bacteria in the gut respond differently to processed foods and cooked foods. Carmody reported that she and Peter Turnbaugh of Harvard University are finding “key differences in the type of bacterial communities” in the guts of mice, depending on whether they were fed chow or cooked meat.

Why does all of this matter? Because we’re in the midst of an obesity epidemic and counting calories has been misleading, said David Ludwig, a pediatric endocrinologist at Children’s Hospital Boston and Harvard Medical School.

Many of us simply roll our eyes and click away when yet another medical study contradicts the last study—so what else is new? Coffee’s bad for you, until it’s good for you—and so is red wine. Antioxidants are essential, or they’re useless. And so on. Contradictory studies are an essential part of the science-news stream—and, in fact, an important part of science itself. But that doesn’t make it any less frustrating.

The fact that it didn’t, and that the two studies conflict, has unintentionally revealed a different truth about diet and aging. In both studies, the monkeys that ate less were healthier by a number of measures—and suffered far less from age-related disease. Even better, when taken together, both studies reveal a different path toward living a healthier life—one that doesn’t require self-starvation.

Over the years, various researchers have shown that caloric restriction can extend life in bats, dogs, and even spiders, and on down to nematode worms and single-celled organisms like yeast. After decades of work, it remains the only way known to increase maximum lifespan. So a lot is riding on the concept, scientifically speaking.

In the 1990s, Leonard Guarente of MIT discovered a class of longevity genes in yeast called sirtuins that appear to be activated by a lack of food. Sirtuins appeared to be “conserved” in evolution, meaning that they appear in nearly all species, on up to humans. Sirtuins are thought to have evolved as a way to enable animals to survive periods of famine. They seem to work by regulating certain metabolic pathways and reduce the amount of damage cells endure.

If researchers could somehow identify and isolate that mechanism, they’d be that much closer to some kind of longevity pill. Except for one inconvenient fact: Caloric restriction itself does not always work.

While 80 percent of the monkeys were still alive, the restricted animals had better measures of cardiovascular health, hormone levels, and blood-sugar management, an early indicator of diabetes risk. So it came as a bit of a surprise, eight years later, to find that the hungry monkeys are not actually living longer.

In fact, caloric restriction really seemed to work best in standard laboratory mice. This may be because they are predisposed to eat a lot, gain weight, and reproduce early—and thus are more sensitive to reduced food intake. (Slate’s Daniel Engber has written about how overfed lab mice have distorted scientific research.)

But in a long-awaited, well-funded monkey study like this, an “odd” result could not be ignored. Still stranger was the fact that even though the underfed monkeys were healthier than the others, they still didn’t live longer. They had lower incidence of cardiovascular disease, as well as diabetes and cancer—and when these diseases did appear, they did so later

At first, it seemed like a scientist’s nightmare: The control group is indistinguishable from the test group. In clinical trials, a result like this would kill any drug candidate. Then de Cabo took a closer look at a seemingly minor difference between the Wisconsin and NIA studies: the animals’ diets.

Furthermore, the NIA diet consisted of 4 percent sucrose—while in the Wisconsin diet, sucrose accounted for some 28 percent of the total calories.

“In physics, a calorie is a calorie,” says de Cabo. “In nutrition and animal physiology, there is more and more data coming out that says that the state of the animal is going to depend more on where the calories are coming from.”

In his study based on the two-year experience, Walford reported that the main effect of caloric restriction was to drastically lower his fellow crew members’ cholesterol levels, to 140 and below—well below the average for people in the industrialized world. Walford concluded that a calorie-restricted diet would have the same beneficial effects that he and other scientists had observed in mice.

Several studies have shown that excessive leanness—seen often in calorie-restricting humans—can be as risky as obesity. Taken together, these studies suggest that the optimal body-mass index is about 25, which is on the verge of being overweight.

But if it’s OK to be almost overweight, it might not pay to go beyond that. Another key difference between the two monkey studies has to do with the definition of “ad libitum.” While the Wisconsin control-group monkeys were allowed to stuff themselves, with the equivalent of an all-you-can-eat buffet for several hours at feeding times, the NIA monkeys were given a fixed amount of food. “You could view it as the Wisconsin monkeys were overindulging, like the rest of the American population,” says Rozalyn Anderson, a member of the Wisconsin team. Compared with           their Wisconsin brothers, then, the NIA monkeys in the non-calorie-restricted control group were arguably practicing a mild form of calorie restriction—and that, Anderson suggests, might have made a difference.

A report published last year in the International Journal of Behavioral Nutrition and Physical Activity, which reviewed seven studies on the topic, found that "calorie labeling does not have the intended effect of decreasing calorie purchasing or consumption."

New regulations requiring operators of restaurants with 20 or more outlets to post calories on menus are expected to take effect by the end of next year.

Glenn Kikuchi, owner of 10 McDonald's franchises in Maryland, said he's already seen signs that the highlighted calorie counts are having an effect. "I see that a lot of the moms are looking at it, but also, curiously enough, the teenagers are looking at it, too," Mr. Kikuchi said.

Inorganic arsenic is certainly a toxin, as was made famous in the movie, Arsenic and Old Lace. It is the primary variety released from rocks into water, and the main concern for human health.

Attention to arsenic in the environment by the Environmental Protection Agency, and in our food by the FDA, can only be a good thing, advancing food safety. Eating a variety of whole grains, for those without reasons to avoid them such as gluten sensitivity, is good for health in general—and may also reduce arsenic intake.

since we can't have perfectly pure food, the operative question in the real world is: Which of the available choices are best for health?

Similarly, there is more arsenic in brown rice than white, but the health benefits of eating a whole grain may outweigh that.

We have known for decades that the four leading causes of chronic disease and premature death in industrialized countries are smoking, poor dietary pattern, lack of physical activity, and obesity. Yet these four are routinely ignored or neglected by people who get very worked up over the latest chemical threat in our food or environment.

The tendency when a chemical threat is highlighted in the news is to think the threat itself is new, and the consequences are unknown, and in the future. But if arsenic in rice or other foods does actually contribute to cancer risk, it has been doing so for years.

the notion that there is a spike in cancer or other disease rates looming around the next bend is misguided; we are already around that bend, and any harms of arsenic are already part of the epidemiologic landscape we know.

Perfectly pure food is, alas, not available on this planet. So those of us living here should focus on net health effects rather than the media hype du jour, and do the best we can with the food supply we've got.

“If anyone in the food industry ever doubted there was a slippery slope out there,” Mudd said, “I imagine they are beginning to experience a distinct sliding sensation right about now.”

his plan would start off with a small but crucial move: the industry should use the expertise of scientists — its own and others — to gain a deeper understanding of what was driving Americans to overeat. Once this was achieved, the effort could unfold on several fronts.

Mudd proposed creating a “code to guide the nutritional aspects of food marketing, especially to children.”

What happened next was not written down. But according to three participants, when Mudd stopped talking, the one C.E.O. whose recent exploits in the grocery store had awed the rest of the industry stood up to speak. His name was Stephen Sanger, and he was also the person — as head of General Mills — who had the most to lose when it came to dealing with obesity. Under his leadership, General Mills had overtaken not just the cereal aisle but other sections of the grocery store. The company’s Yoplait brand had transformed traditional unsweetened breakfast yogurt into a veritable dessert. It now had twice as much sugar per serving as General Mills’ marshmallow cereal Lucky Charms. And yet, because of yogurt’s well-tended image as a wholesome snack, sales of Yoplait were soaring, with annual revenue topping $500 million. Emboldened by the success, the company’s development wing pushed even harder, inventing a Yoplait variation that came in a squeezable tube — perfect for kids. They called it Go-Gurt and rolled it out nationally in the weeks before the C.E.O. meeting. (By year’s end, it would hit $100 million in sales.)

“What can I say?” James Behnke told me years later. “It didn’t work. These guys weren’t as receptive as we thought they would be.” Behnke chose his words deliberately. He wanted to be fair. “Sanger was trying to say, ‘Look, we’re not going to screw around with the company jewels here and change the formulations because a bunch of guys in white coats are worried about obesity.’ ”

While the money that they’ve picked from each individual American’s pocket is small, the aggregate is huge for the rent-seeker. And this in turn deepens inequality.

FARM subsidies were much more sensible when they began eight decades ago, in 1933, at a time when more than 40 percent of Americans lived in rural areas. Farm incomes had fallen by about a half in the first three years of the Great Depression. In that context, the subsidies were an anti-poverty program.

Some three-quarters of the subsidies went to just 10 percent of farms. These farms received an average of more than $30,000 a year — about 20 times the amount received by the average individual beneficiary last year from the federal Supplemental Nutrition Assistant Program, or SNAP, commonly called food stamps.

More than 80 percent of the 45 million or so Americans who participated in SNAP in 2011, the last year for which there is comprehensive data from the United States Department of Agriculture, had gross household incomes below the poverty level.

Historically, food stamp programs and agricultural subsidies have been tied together.

The Nobel Prize winning economist Amartya Sen has reminded us that even famines are not necessarily caused by a lack of supply, but by a failure to get the food that exists to the people who need it. This was true in the Bengal famine of 1943 and in the Irish potato famine a century earlier: Ireland, controlled by its British masters, was exporting food even as its citizens died of starvation.

A similar dynamic is playing out in the United States. American farmers are heralded as among the most efficient in the world. Our country is the largest producer and exporter of corn and soybeans, to name just two of its biggest crops. And yet millions of Americans still suffer from hunger, and millions more would, were it not for the vital programs that government provides to prevent hunger and malnutrition — the programs that the Republicans are now seeking to cut back.

While they encourage overproduction, they pay little attention to the quality and diversity of foods our farms produce. The heavy subsidization of corn, for instance, means that many unhealthful foods are relatively cheap.

This is part of the reason that Americans face the paradox of hunger out of proportion to their wealth, along with some of the world’s highest obesity rates, and a high incidence of Type 2 diabetes. Poor Americans are especially at risk for obesity.

Indian friends I met that day and in the following week were puzzled by this news: How could it be that in the richest country of the world there was still hunger?

Their puzzlement was understandable: Hunger in this rich land is unnecessary. What my Indian friends didn’t understand is that 15 percent of Americans — and 22 percent of America’s children — live in poverty.

Someone working full time (2,080 hours a year) at the minimum wage of $7.25 would earn about $15,000 a year, far less than the poverty threshold for a family of four ($23,492 in 2012), and even less than the poverty level of a family of three.

In his famous 1941 “four freedoms” speech, Franklin D. Roosevelt enunciated the principle that all Americans should have certain basic economic rights, including “freedom from want.”

And those numbers increased drastically with the onset of the Great Recession. The number of Americans on food stamps went up by more than 80 percent between 2007 and 2013.

In 2012, for example, two in five SNAP recipients had gross incomes that were less than half of the poverty line.

The amount they get from the program is very small — $4.39 a day per recipient.

The Center on Budget and Policy Priorities estimates that SNAP lifted four million Americans out of poverty in 2010.

with American consumption diminished from what it otherwise would be and production increased, food exports will inevitably increase.

By cutting back on food stamps, we are ensuring the perpetuation of inequality, and at that, one of its worst manifestations: the inequality of opportunity.

To this day, my kids won't eat fresh green beans. There's such a huge difference in texture and taste compared to the canned version that they're honestly like two different foods. None of us will eat homemade macaroni and cheese. If it doesn't come out of a box, it tastes weird. And the list is a mile long. We've eaten these things for so long, we've grown to prefer them to the fresh version.

And just like many poor people, we'd be broke within days of cashing that check, our living room sporting a new TV. Or we'd replace our old computers and all of our furniture. There's a reason many poor people blow through that money instead of saving it for future bills.

When you live in poverty, you're used to your bank account revolving very tightly around a balance of zero. Your work money comes in and goes right back out to bills, leaving you breaking even each month (if you're lucky). That's the life you've gotten used to. It's normal for you.

When a windfall check is dropped in your lap, you don't know how to handle it. Instead of thinking, "This will cover our rent and bills for half a year," you immediately jump to all the things you've been meaning to get, but couldn't afford on your regular income.

Don't misunderstand me here, it's never a "greed" thing. It's a panic thing. "We have to spend this before it disappears."

Have you heard those stories about lottery winners who are bankrupt within a year or two, despite winning millions? That's because they can't turn that off. They can't shake the idea that the money is perishable.

When you don't have the extra cash, you don't know how to handle it when you do get some. When you escape that level of poverty, and you find yourself having extra money for the first time, you eventually learn how to manage it.

Like anything else, it takes practice, and the poor never get the chance.

being the provider of the household, it makes you feel like a failure. And like anything else, that makes you want to overcompensate.

After we exhausted our bank account, my fiance and I looked at the number of boxes around the tree and pointed out that it didn't look like all that much. So we waited until our next check and went back for more.We overcompensated so much in the other direction that we damn near drove ourselves back into the poorhouse.

37 subjects took part, all with self-reported gluten sensitivity who were confirmed to not have celiac's disease. They were first fed a diet low in FODMAPs for two weeks, then were given one of three diets for a week with either 16 grams per day of added gluten (high-gluten), 2 grams of gluten and 14 grams of whey protein isolate (low-gluten), or 16 grams of whey protein isolate (placebo). Each subject shuffled through every single diet so that they could serve as their own controls, and none ever knew what specific diet he or she was eating.

After the main experiment, a second was conducted to ensure that the whey protein placebo was suitable. In this one, 22 of the original subjects shuffled through three different diets -- 16 grams of added gluten, 16 grams of added whey protein isolate, or the baseline diet -- for three days each.

The acute, sudden-onset reactions tend to be caused by antibodies called immunoglobulin E (IgE).

A food intolerance is NOT the same as a food allergy. Many people incorrectly use the words interchangeably. A food allergy is when the body's immune system reacts abnormally to specific foods. No allergic reaction takes place with a food intolerance.

Lactose intolerance This causes diarrhoea and abdominal symptoms (bloating and pain) after milk is drunk or dairy products are eaten.

Direct effects of foods and additives Certain foods and chemicals in foods may directly affect the body and cause symptoms.

Food avoidance Some people, especially children, may develop physical symptoms such as feeling sick and diarrhoea if they eat, or are offered, foods they have come to dislike.

The symptoms of food intolerance occur usually a few hours after eating the food. Allergic reactions happen much more quickly.

Food intolerances are never life-threatening. Some allergies are as they can cause anaphylaxis.

In the western world, 6-8 children in 100 and 3-4 adults in 100 are thought to have a food allergy. In the UK, 2 babies in 100 develop an allergy to protein in cow's milk (cow's milk protein allergy). The number of people with food allergies seems to be rising.

Symptoms

Symptoms of an allergic reaction can include: Atopic eczema (classical eczema) that is seen in allergy-prone (atopic) families - often those with hay fever and asthma too. Gastro-oesophageal reflux which is vomiting that is generally effortless. Loose and/or frequent stools (poo). Constipation. Blood or mucus in the stools. Redness around the anus. Tiredness. Pallor. Poor growth. This is often seen in children with a non-IgE food allergy. Young children, particularly those with digestive symptoms, should be regularly weighed. Weight should be plotted on a growth chart. This allows medical professionals such as GPs and health visitors to see if growth is slow.

Symptoms of a food intolerance vary widely and can include: Bloating and abdominal pain. Diarrhoea or loose stools (poo). Skin rashes and itching. Some of these symptoms are the same as those that can be caused by a non-IgE food allergy. So this shows how complicated it can be to determine whether you have an allergy or an intolerance.

Skin prick test. This is usually done in a specialist hospital allergy clinic. Because an anaphylactic reaction is possible, there needs to be access to resuscitation equipment including adrenaline.

Blood tests. Blood tests can detect if your blood contains specific IgE antibodies. So, if you had allergic reactions to peanuts, your blood might contain antibodies to peanuts.

If a non-IgE food allergy is suspected, elimination and challenge can be used to try to confirm the diagnosis of allergy. This is only really appropriate when it seems clear which foodstuff is causing the problem.

You may see many commercial companies offering allergy testing, particularly on the internet. Be very wary of these. The following tests have no medical evidence behind them - that is, they cannot be relied upon to give any accurate results.

The only real treatment for food allergy and intolerance is to avoid that food. This is very important if an anaphylactic reaction has occurred.

Dieticians are qualified health professionals. They can assess, diagnose and treat diet and nutrition problems.

f you have a food allergy or intolerance, after seeking medical advice, a dietician can be a useful person to see for further help and advice.

Coeliac disease is NOT a food allergy, nor is it a food intolerance. It is an autoimmune disease which means that the immune system (which normally protects the body from infections) mistakenly attacks itself.