Figure 4.

The relationship between protein and carbohydrate intake and median lifespan in mice. The lifespan remains constant along the black isolines on the surfaces, and the numbers on surfaces indicate the magnitude of lifespan (in weeks) along the isolines. The shortest lifespan is shown in blue and the longest lifespan in red. Mice fed diets with the lowest protein–carbohydrate ratio (red line) had the longest lifespan, while those fed high protein–low carbohydrate diets had the shortest lifespan [185,218] (Reprinted with permission from refs. [185,218]. Copyright 2021 Solon-Biet, SM, Simpson SJ).