Homo sapiens

The obesity epidemic is among the greatest public health challenges facing the modern world, notably Australia. Regarding dietary causes, most emphasis has been on changing patterns of fat and carbohydrate consumption. In contrast, the role of protein has largely been ignored, because

  • it typically comprises only 15% of dietary energy, and
  • protein intake has remained near constant within and across populations throughout the development of the obesity epidemic.

We have shown that, paradoxically, these are precisely the two conditions that potentially provide protein with the leverage both to drive the obesity epidemic through its effects on food intake, and perhaps to assuage it. We have formalized this hypothesis in a mathematical model, which arose originally from work on herbivorous insects. Existing data support the predictions of the model, and we are engaged in testing it further. The implications for public health are considerable.

homo sapiens


  1. Simpson, S.J. & Raubenheimer, D. (2005). Obesity: the protein leverage hypothesis. Obesity Reviews, 6, 133-142.
  2. Simpson, S.J. Batley, R. & Raubenheimer, D. (2003) Geometric analysis of macronutrient intake in humans: the power of protein? Appetite, 41, 123-140.