How does it all add up? In the context of the average American diet, which is mostly poor-quality carbohydrates such as starches and sugars, the amount of saturated fat eaten doesn’t significantly increase or decrease health risk. This is likely why it’s not related to risk of heart attacks when we look at large population studies.
Q: What has been the effect of the move to cut down on saturated fat in the United States?
A: In the last few decades, total-fat and saturated-fat consumption has gone down, but consumption of refined carbohydrates has soared. Low-fat versions of packaged foods, loaded with refined carbohydrates, sugars and salt, now flood the market. When people replace saturated fat with refined carbohydrates, they are unlikely to improve their health and may worsen it. That’s because these kinds of carbohydrates are more likely than saturated fat to raise the risk of heart disease and type 2 diabetes.
Q: So has the recommendation to reduce saturated fat done more harm than good?
A: The emphasis on saturated fat misleads people into thinking that foods low in saturated fat are healthier when they’re not. For example, low-saturated-fat processed meats are not healthy choices. And the desire to reduce saturated fat sometimes steers people away from foods that contain that fat but are actually healthy.
Q: What’s an example of a healthy food that contains saturated fat?
A: The average avocado contains about 4.5 grams of total fat, including about half a gram of saturated fat. This small amount has been enough for many people to suggest that you should avoid avocados. But this fruit also contains four grams of unsaturated fats, similar to those found in olive oil, as well as phytochemicals that are healthy.
Dairy is another example of how a focus on saturated fat can lead people astray. We’ve tended to treat all foods that contain saturated fat the same—unprocessed red meat, processed meat, cheese, yogurt and milk. But each of those foods contains a variety of components, some good and some not so good. Given equivalent serving sizes, processed meat is associated with far higher risks of type 2 diabetes and heart disease than unprocessed meat, even though their saturated-fat content is about the same. Many low-saturated-fat processed deli meats, which are currently marketed as healthy choices, could be much worse for your health than unprocessed red meats that contain more saturated fat. Similarly, even though dairy foods are the top source of saturated fat in the U.S., people who eat the most dairy do not have a higher risk of heart attacks and actually may have a lower risk of type 2 diabetes and stroke.
Q: Do researchers know if full-fat milk is healthier than reduced fat?
A: We don’t have firm evidence. Very few long-term studies have compared the health effects of full-fat dairy versus reduced-fat dairy. Even fewer have compared the health effects of different types of dairy, such as butter, milk, cheese and yogurt. The few that have been done have shown mixed results. Some suggest that reduced-fat dairy is better for heart disease or type 2 diabetes risk. Others suggest that whether you consume full-fat or -reduced-fat dairy, the risks are the same. Still others suggest that full fat may be better, because there may be specific fatty acids in dairy fat, or compounds that go along with the fat, that protect against disease. I don’t think we have enough evidence to alter the existing dietary guidelines that recommend low-fat dairy. But we also don’t have clear evidence that low-fat dairy is a better choice than whole-fat dairy.