Hungry? Better Eat Whey than Soy! Rats Receiving Soy Supplement Consume More Calories.

Lately, whey protein is all the rage. Rightly, as it seems! A recent study on the effect of protein supplementation on appetite and calorie consumption in rats showed that whey is way superior to soy protein in inducing satiety and reducing caloric intake.

For 10 weeks rats were fed a standard diet (control), or a high protein diet, with either 24% whey or isoflavone-free soy protein added to the chow. Both dietary interventions, i.e. the increase in protein intake, led to significantly reduced body weight and body fat gains, but ...

[...] cumulative food intake measured over the 10-week study period was lower in the HP-W vs. control and HP-S groups (P < 0.01).[...] Plasma concentrations of total GLP-1 [glucagon-like peptide 1] were higher in HP-W and HP-S vs. control group (P < 0.05), whereas plasma CCK, PYY, and leptin did not differ among the three groups.

In how far the reduced caloric intake is retractable to the GLP-1 (exclusively?) is questionable. What is certain is that GLP-1 has for quite some time been investigated as a potential treatment of diabetes. It plays a major role in insulin release and blood glucose management induces satiety and increases insulin sensitivity.

If you still think this is no reason to spend the additional bucks on whey, I suggest you listen to last weeks interview with Dr. Scott Connelly on Super Human Radio - I bet you won't have joy with soy, anymore ;-)