How the Sugar Industry Shaped What We Blame

The story begins with a straightforward business calculation. In the mid-1950s, the trade group representing the sugar industry recognised something that was good for sales and awkward for public health. Internal documents from 1954 noted that if Americans could be persuaded to adopt low-fat diets, per-person sugar consumption would rise by more than a third, because the calories cut from fat would largely be replaced by carbohydrate, much of it sugar.

That is the crucial context for everything that followed. The industry had a clear financial reason to want fat, not sugar, to be seen as the dietary danger. When a stream of research money then flowed toward blaming fat, it did not happen in a vacuum. It happened alongside a documented interest in exactly that outcome.

In 1965 the Sugar Research Foundation sponsored its first project on heart disease: a literature review. According to the internal documents later analysed by researchers and published in 2016, the foundation did far more than write a cheque. It set the review's objective, contributed articles to be included, and received drafts as the work took shape. The review singled out fat and cholesterol as the dietary causes of coronary heart disease and downplayed the evidence that sugar might also be a culprit.

It was published in a leading medical journal in 1967, and the sugar industry's funding and involvement were not disclosed. To readers and, in turn, to the doctors and policymakers who relied on such reviews, it looked like an independent assessment of the evidence. The researchers who uncovered the documents concluded that the industry had helped shape the scientific debate on heart disease to serve its own interests, at a moment when that debate was still open.

The review was not the only case. A separate analysis of industry documents, published in 2017, described an animal study the sugar industry funded between 1967 and 1971, sometimes called Project 259. It compared animals fed high-sugar diets with those fed high-starch diets, and early results pointed in an uncomfortable direction: sugar appeared to be associated with raised blood fats and with elevated levels of an enzyme that had been linked to bladder cancer.

Rather than following that finding to publication, the funding organisation ended the project without publishing the results. The researchers who later reviewed the documents argued that, had the work been completed and made public, it would have strengthened the case for scrutinising sugar as a risk for both heart disease and cancer, years earlier than the wider scientific community got there. Instead, the inconvenient result stayed in a drawer.

The downstream effects were enormous, even if no single document can be blamed for all of them. Fat became the defining dietary enemy of the following decades. Guidelines pushed low-fat eating, and the food industry answered with a wave of low-fat products. The problem is that fat carries a lot of flavour, and when you strip it out, something has to replace it. Very often, that something was sugar.

So a generation dutifully bought low-fat yoghurts, cereals, and ready meals that were quietly loaded with added sugar, believing they were making the healthy choice. The single-villain framing, fat bad, everything-else fine, turned out to be both too simple and, in part, purchased. It is a large reason why sugar took so long to get the attention it now receives.

It would be easy to flip the old story and declare sugar the sole villain and fat innocent all along. That would repeat the same mistake in the opposite direction. The real conclusion is more grown-up. Saturated fat still matters for heart health, sugar in excess still matters, and no single ingredient is the whole story. What the documents expose is not which food to fear, but how the science we trust can be nudged by money when nobody is checking who paid.

That is a useful habit to keep. When a study or a headline conveniently exonerates one food or damns another, it is worth asking who funded it and what they had to gain. Nutrition research is far more transparent now than it was in the 1960s, with disclosure rules that did not exist then. But the underlying lesson holds: follow the money, distrust single-villain stories, and judge your diet on the overall pattern rather than on whichever ingredient is currently in the dock.