The Sugar Conspiracy is a long article that argues that the epidemic of obesity was caused by nutritionists, a group that has for years almost unanimously promoted a low-fat and therefore a high carbohydrate diet: "Harder, too, to deflect or smother the charge that the promotion of low-fat diets was a 40-year fad, with disastrous outcomes, conceived of, authorised, and policed by nutritionists."
What happened in nutrition is reminder that the process of science is not the pure pursuit of truth that some think it is and that peer review is not a guarantee of quality. Peer review can be stifle criticism and protect incumbent theories from evidence. Personalities, reputations, and politics play important roles in science and incentives matter. From the article: "When I asked Lustig why he was the first researcher in years to focus on the dangers of sugar, he answered: 'John Yudkin. They took him down so severely – so severely – that nobody wanted to attempt it on their own.'"