With the salad days of summer behind us, and dark, cold days approaching, fat is in season. The holidays, and the accompanying onslaught of rich feasts, present a timely opportunity to think about fat. I used to assume we ate more fat in winter because our bodies wanted to pack on some extra insulation against the cold, but the evidence in support of this seemingly obvious notion—that dietary fat leads to weight gain—is being challenged. Beyond the relationship between fat and health, it’s beginning to look like other deeply held beliefs about fat might be wrong as well.
Long considered a threat to public health, some recent books, such as Big Fat Surprise by Nina Teicholz, and before that Good Calories, Bad Calories by Gary Taubes, have challenged the idea that dietary fat is the cause of obesity, heart disease and other associated ailments. Big Fat Surprise was lauded by the Economist (among other media), which called it 2014’s “most surprising diet book.” Both Teicholz and Taubes argue that low-fat and non-fat diets, rather than fat, are behind the rise in obesity and related diseases. And Teicholz makes a strong case that fat, especially saturated fat, is actually good for you. As we speak, many government agencies, like USDA, which have long championed low-fat diets, are tip-toeing away from their anti-fat stances.
Along these lines, a study published this November found that “dietary and plasma saturated fat are not related,” after a doubling of dietary saturated fat intake showed no significant increase in blood lipids. In other words, even if there is a link between blood lipids (aka fat) and heart disease, factors other than dietary intake of fat, such as carbohydrate intake, are what determine blood lipid levels. It should be noted that this study was funded, in part, by the Dairy Research Institute, the National Cattlemen’s Association and the Egg Nutrition Center, all of which must have been pleased with the results. But other studies have shown similar results.
An absence of correlation with heart disease has also been shown with cholesterol intake: A comparison of cholesterol intake versus heart disease across various cultures, summarized in this short video, shows that Australian aborigines have the lowest level of cholesterol intake and the highest level of death from heart disease, while the Swiss have the highest level of cholesterol intake and the lowest rate of death from heart disease.
Other shifts in our understanding of fat are underway as well. One such aspect, much less discussed, is the science of how fat is perceived by the body.
A friend of mine who went to cooking school was fond of saying, “fat is flavor.” This idea has infiltrated the restaurant industry to the point where recipes for many dishes might as well be written as, “Heat edible materials, add butter, and serve.” It isn’t the most nuanced of culinary strategies, but it works.
According to traditional scientific understanding of flavor perception, however, fat doesn’t have any flavor. This isn’t to say anyone ever claimed fatty foods aren’t delicious—that is beyond debate. But it was thought that other qualities of fat made this so. It’s long been understood that the texture of fat, and its creamy, lubricating qualities, are what makes food taste better, and easier to chew and swallow.