Higher protein to carbohydrate ration stabilizes blood glucose
Many experts in the athletic nutrition field feel that protein consumption should not go beyond 1 grm/pound of bodyweight because excess protein will be converted to glucose. They feel that this would offset the benefits of a low carb diet. The following study shows that a higher protein/carb ratio (~1.5 gms/pound bw) stabilizes blood glucose levels and reduces the insulin response.
Increased Dietary Protein Modifies Glucose and Insulin Homeostasis in Adult Women during Weight Loss.
Layman DK, Shiue H, Sather C, Erickson DJ, Baum J.
Department of Food Science and Human Nutrition, Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
Amino acids interact with glucose metabolism both as carbon substrates and by recycling glucose carbon via alanine and glutamine; however, the effect of protein intake on glucose homeostasis during weight loss remains unknown. This study tests the hypothesis that a moderate increase in dietary protein with a corresponding reduction of carbohydrates (CHO) stabilizes fasting and postprandial blood glucose and insulin during weight loss. Adult women (n = 24; >15% above ideal body weight) were assigned to either a Protein Group [protein: 1.6 g/(kg. d); CHO <40% of energy] or CHO Group [protein: 0.8 g/(kg. d); CHO >55%]. Diets were equal in energy (7100 kJ/d) and fat (50 g/d). After 10 wk, the Protein Group lost 7.53 +/- 1.44 kg and the CHO Group lost 6.96 +/- 1.36 kg. Plasma amino acids, glucose and insulin were determined after a 12-h fast and 2 h after a 1.67 MJ test meal containing either 39 g CHO, 33 g protein and 13 g fat (Protein Group) or 57 g CHO, 12 g protein and 14 g fat (CHO Group). After 10 wk, subjects in the CHO Group had lower fasting (4.34 +/- 0.10 vs 4.89 +/- 0.11 mmol/L) and postprandial blood glucose (3.77 +/- 0.14 vs. 4.33 +/- 0.15 mmol/L) and an elevated insulin response to meals (207 +/- 21 vs. 75 +/- 18 pmol/L). This study demonstrates that consumption of a diet with increased protein and a reduced CHO/protein ratio stabilizes blood glucose during nonabsorptive periods and reduces the postprandial insulin response.
Nice post... it kind of concurs with my non-scientific findings of late. I switched to about 350 grams of protein and 200-250 grams of complex carbs (except a banana post work-out). I have found that my energy levels are steady throughout the day and that, unlike during a low carb diet, I actually have volume and pump in my muscles.
Gluconeogenesis will of course modulate insulin release since the amount of CHO is limited by the kinetics of the conversion of excess protein to CHO. This study highlights one of the many reasons low carb dieting it so effective - its costs the body energy to make the CHO it needs.