Why is it an either or proposition?
Because high-protein diets promote high cortisol levels, which promotes diabetes, whereas a high-carbohydrate diet promotes high insulin levels, which prevents diabetes.
Having a high ratio of starch to meat would be fine, but an even ratio, or a high ratio of meat to starch wouldn't.
Life Sci. 1987 May 4;40(18):1761-8.
Diet-hormone interactions: protein/carbohydrate ratio alters reciprocally the plasma levels of testosterone and cortisol and their respective binding globulins in man.
Anderson KE, Rosner W, Khan MS.
Abstract
The aim of this study was to determine if a change in protein/carbohydrate ratio influences plasma steroid hormone concentrations. There is little information about the effects of specific dietary components on steroid hormone metabolism in humans. Testosterone concentrations in seven normal men were consistently higher after ten days on a high carbohydrate diet (468 +/- 34 ng/dl, mean +/- S.E.) than during a high protein diet (371 +/- 23 ng/dl, p less than 0.05) and were accompanied by parallel changes in sex hormone binding globulin (32.5 +/- 2.8 nmol/l vs. 23.4 +/- 1.6 nmol/l respectively, p less than 0.01). By contrast, cortisol concentrations were consistently lower during the high carbohydrate diet than during the high protein diet (7.74 +/- 0.71 micrograms/dl vs. 10.6 +/- 0.4 micrograms/dl respectively, p less than 0.05), and there were parallel changes in corticosteroid binding globulin concentrations (635 +/- 60 nmol/l vs. 754 +/- 31 nmol/l respectively, p less than 0.05). The diets were equal in total calories and fat. These consistent and reciprocal changes suggest that the ratio of protein to carbohydrate in the human diet is an important regulatory factor for steroid hormone plasma levels and for liver-derived hormone binding proteins.
Edited by misterE, 13 November 2015 - 01:57 PM.