Why our food is making us fat

Burgers became bigger. Fries, fried in corn oil, became fattier. Corn became the engine for the massive surge in the quantities of cheaper food being supplied to American supermarkets: everything from cereals, to biscuits and flour found new uses for corn.

As a result of Butz's free-market reforms, American farmers, almost overnight, went from parochial small-holders to multimillionaire businessmen with a global market. One Indiana farmer believes that America could have won the cold war by simply starving the Russians of corn. But instead they chose to make money. By the mids, there was a surplus of corn. Butz flew to Japan to look into a scientific innovation that would change everything: the mass development of high fructose corn syrup HFCS , or glucose-fructose syrup as it's often referred to in the UK, a highly sweet, gloppy syrup, produced from surplus corn, that was also incredibly cheap.

HFCS had been discovered in the 50s, but it was only in the 70s that a process had been found to harness it for mass production. HFCS was soon pumped into every conceivable food: pizzas, coleslaw, meat. It provided that "just baked" sheen on bread and cakes, made everything sweeter, and extended shelf life from days to years. A silent revolution of the amount of sugar that was going into our bodies was taking place. In Britain, the food on our plates became pure science — each processed milligram tweaked and sweetened for maximum palatability.

And the general public were clueless that these changes were taking place. There was one product in particular that it had a dramatic effect on — soft drinks. As a market leader, Coke's decision sent a message of endorsement to the rest of the industry, which quickly followed suit. It was two-thirds the price of sugar, and even the risk of messing with the taste was a risk worth taking when you looked at the margin, especially as there were no apparent health risks. At that time, "obesity wasn't even on the radar" says Cardello.

But another health issue was on the radar: heart disease, and in the mids, a fierce debate was raging behind the closed doors of academia over what was causing it. But Yudkin's work was rubbished by what many believe, including Professor Robert Lustig , one of the world's leading endocrinologists, was a concerted campaign to discredit Yudkin.

Much of the criticism came from fellow academics, whose research was aligning far more closely with the direction the food industry was intending to take. Yudkin's colleague at the time, Dr Richard Bruckdorfer at UCL says: "There was a huge lobby from [the food] industry, particularly from the sugar industry, and Yudkin complained bitterly that they were subverting some of his ideas. The food industry had its eyes on the creation of a new genre of food, something they knew the public would embrace with huge enthusiasm, believing it to be better for their health — "low fat".

It promised an immense business opportunity forged from the potential disaster of heart disease. But, says Lustig, there was a problem. Overnight, new products arrived on the shelves that seemed too good to be true. Low-fat yoghurts, spreads, even desserts and biscuits. All with the fat taken out, and replaced with sugar. Britain was one of the most enthusiastic adopters of what food writer Gary Taubes , author of Why We Get Fat, calls "the low-fat dogma", with sales rocketing.

By the mids, health experts such as Professor Philip James , a world-renowned British scientist who was one of the first to identify obesity as an issue, were noticing that people were getting fatter and no one could explain why. The food industry was keen to point out that individuals must be responsible for their own calorie consumption, but even those who exercised and ate low-fat products were gaining weight.

In the proportion of people with a BMI of over 30 classified as obese was just 1. By the figures had risen to And no one was joining the dots between HFCS and fat. Moreover, there was something else going on. The more sugar we ate, the more we wanted, and the hungrier we became. At New York University, Professor Anthony Sclafani , a nutritionist studying appetite and weight gain, noticed something strange about his lab rats. When they ate rat food, they put on weight normally. But when they ate processed food from a supermarket, they ballooned in a matter of days.

Their appetite for sugary foods was insatiable: they just carried on eating. According to Professor Jean-Marc Schwarz of San Francisco hospital, who is currently studying the precise way in which the major organs of the body metabolise sugar, this momentum creates "a tsunami" of sugar. The effect this has on different organs in the body is only now being understood by scientists. Around the liver, it coalesces as fat, leading to diseases such as type-2 diabetes.

But a review of the literature in The Obesity Epidemic: Science, Morality, and Ideology by Michael Gard and Jan Wright asserts that there is no evidence that food intake levels have increased in industrialized countries, or that activity levels have declined. According to Gard and Wright, some studies even suggest a reduction in energy intake over the past several decades.

Julie Guthman, a professor of community studies at the University of California, Santa Cruz, points out in her new book, Weighing In , that the amount of calories consumed across racial lines and income levels varies little, according to a study by the United States Department of Agriculture USDA. This is despite the fact that obesity and overweight do vary across racial lines and income levels: Poorer people tend to be more obese, and African Americans and Latinos have higher rates of obesity than do whites.

This means there must be some other mechanism, Guthman says, besides excess calories, in the varying levels of obesity. In her book, she refers to the possible role of environmental factors like exposure to obesogens and other toxins, stress, and non-nutritional aspects of food. Guthman would like to see stronger regulation on the part of the government, and a discussion that focuses more on how food is produced and not just on how much is eaten.

This seems to fit with Marion Nestle 's approach to educating people on weight loss. Nestle is the co-author of a new book on the subject, Why Calories Count. They might have something to do with obesity -- I suppose it's not impossible -- but why invoke complicated explanations when the evidence for calories is so strong? Let's say obesogens affect a body weight regulatory factor, which they very well might do.

But so what? Weight is regulated by more than a hundred biological factors, and these are redundant, which means that if something goes wrong with one of them the others fill in the deficit. The "so what," Guthman says, is that "We really don't understand the science enough, and there's new evidence in the science that completely re-shifts how we think about these things. According to Blumberg, the food industry would like to discredit emerging research on obesogens. In contrast, not a single industry-funded or -conducted study has found any hazard associated with BPA.

Can we afford to continue to frame the discussion simply in terms of calories in and calories out? Or by looking only at conventional categories like fat, protein, and carbohydrates and diary, meat, grains, and vegetables? Given the proliferation of industrial pollutants and the ultra-processing of foods in our current food systems, it seems that we can't. We want to hear what you think about this article. Submit a letter to the editor or write to letters theatlantic. Skip to content.

Sign in My Account Subscribe. The Atlantic Crossword. The Print Edition. Latest Issue Past Issues. Only through November Try subscriber newsletters for free. We begin to feel weak and hungry. And we eat more. If this understanding of obesity is correct, the energy-balance model has obesity backward: Overeating is a response to growing fatter that is, to our fat tissues hoarding calories rather than an underlying cause of growing fatter.

Further, whatever raises insulin levels excessively in our blood is likely to be the true culprit in obesity. In place of the energy-balance model, the Clinical Nutrition article proposes a carbohydrate-insulin model because the pancreas releases more insulin in response to processed carbohydrates than to any other foods. Our obesity epidemic took off in the s, it follows, not simply because we started to eat more calories in the form of processed food, but because we began to replace the healthy fats in our diet with refined sugars and grains.

To appreciate how obesity researchers could have missed the hormonal connection to weight gain for so long, consider that refined sugars and grains, the same molecules that elevate insulin levels, also happen to be a source of calories.

The great mistake, according to proponents of the carbohydrate-insulin model, was blaming refined carbohydrates primarily for their energy content, their calories, rather than for their influence on our hormones. For the public, scientific debates about the nuances of obesity and the way our bodies store and access energy can seem like so much squabbling over minor points.

But given the link between obesity and chronic disease, there may be no single question in American life more important than which side of this debate is correct. If the carbohydrate-insulin model is correct — and its proponents acknowledge that we need more research before saying so with absolute certainty — it suggests a radically different approach to restoring health to the nearly three-quarters of American adults who are overweight. Instead of aiming to eat fewer calories, an approach that follows from the energy-balance model and that has failed for so many of us, we should replace the refined carbohydrates in our diets with healthy fats and protein without much concern for counting calories.

Such a high-fat, low-carbohydrate diet would lower insulin levels and allow our fat cells to release the calories they are hoarding.

Whether the debate among scientists leads to a revolution in how we understand the science of getting fat remains to be seen. Column: Fraternities are incubators of sexual assault and other violence. Why is USC defending them?