Fig.1.

Dietary fat composition changes over human existence. Human food composition has changed considerably over the course of time. Dietary fat accounted for at most 25% of total calories in the early Hunter/Gatherer time period but has increased to as much as 40% in the present day. The fat composition in the diet has also changed over time, with a higher ratio of saturated fat to polyunsaturated fat and a greater omega-6 to omega-3 ratio in the modern era when compared to earlier time periods. (Figure adapted from [4]).