What's the beef with butter?

Monitoring saturated fat intake is a good idea for everyone

- ALICE CALLAHAN

For decades, nutrition experts and health officials have warned against eating too much saturated fat. Red meat, full-fat dairy products, fried foods and other big sources of the nutrient can raise your cholesterol, they have said, and with it the risk of cardiovascular disease.

But Robert F. Kennedy Jr and other federal health officials, along with some proponents of the Make America Healthy Again (MAHA) movement, have taken a different stance — suggesting that the fats have been unfairly demonised and that the evidence to prove that they are harmful is insufficient.

Mr Kennedy, the US health secretary, has been dismissive of expert consensus and said that the next edition of the Dietary Guidelines for Americans, expected in early 2026, will “stress the need to eat saturated fats”.

Why the potential about-face on decades of guidance? We asked nutrition experts to break down the evidence.

All fatty acids are categorised into two main groups according to their molecular structures.

Saturated fats, which tend to be solid at room temperature, are predominant in animal products like butter, cheese, beef and pork as well as certain oils like coconut oil and palm oil.

Unsaturated fats are abundant in fish and foods like avocados, nuts, seeds and cooking oils like olive oil and soybean oil. These types of fat tend to be liquid at room temperature.

Since the 1950s and 1960s, studies have consistently found cardiovascular benefits from limiting saturated fats, said Kevin Klatt, an assistant professor of nutritional sciences at the University of Toronto.

Small clinical trials from the 1950s, for instance, found that when adults replaced saturated fats (from foods like butter or coconut oil) with unsaturated fats (from sources like sunflower oil or corn oil), their blood cholesterol levels decreased.