- A diet containing 38% fat: 16% saturated (SFA), 12% monounsaturated (MUFA) and 6% polyunsaturated (PUFA)
- A diet containing 38% fat: 8% SFA, 20% MUFA and 6% PUFA
- A diet high in unrefined carbohydrate, containing 28% fat (8% SFA, 11% MUFA and 6% PUFA)
- A diet high in unrefined carbohydrate, containing 28% fat (8% SFA, 11% MUFA and 6% PUFA) and an omega-3 supplement (1.24 g/day EPA and DHA)
One of the questions one could legitimately ask, however, is whether SFA have a different effect on people with metabolic syndrome. Maybe the inflammation and metabolic problems they already have make them more sensitive to the hypothetical damaging effects of SFA? That's the question the first study addressed, and it appears that SFA are not uniquely harmful to insulin signaling in those with metabolic syndrome on the timescale tested.
It also showed that the different diets did not alter the proportion of blood fats being burned in muscle, as opposed to being stored in fat tissue. The human body is a remarkably adaptable biological machine that can make the best of a variety of nutrient inputs, at least over the course of 12 weeks. Metabolic damage takes decades to accumulate, and in my opinion is more dependent on food quantity and quality than macronutrient composition.