I don't want to steal Harris Lieberman's thunder, either, but I strongly suspect that unless there are kinds of cognitive function that we cannot measure easily, you will not see much in the way of any effect on cognitive performance.
Finally, I think that there are just insufficient data to talk about gender differences so far.
HARRIS LIEBERMAN: I just want to make a comment. With regard to formulating a recommendation, remember that the soldiers who come into the Army are eating an American diet and have eaten an American diet their whole lives, so that a suggestion that I make is not to recommend a change in the American diet or even a change in the soldier's diet in garrison, because we really cannot change diets that drastically; we simply want recommendations on what we are going to feed in those times when we go out into the field, and particularly when we go into combat. What we really need is a recommendation for a combat ration.
ROBERT NESHEIM: Dr. Butterfield?
GAIL BUTTERFIELD: Let me ask my usual question of the speakers. One of the problems with military troops in the field is that their energy intake is dramatically reduced. How do you think that reduction will affect these various factors?
MICHAEL RENNIE: Well, there is some dramatic evidence from Stroud and Fiennes' trans-Antarctic walk, in which they expended huge amounts of energy, greater amounts of energy than Tour do France cyclists expend, and yet their energy intakes were certainly less than that, and they lost very large amounts of weight.
What is quite interesting is that in the study that Stroud and Alan Jackson and John Waterlow published in the British Journal of Nutrition , although it cannot really be described as a scientific study, given the way the controls were performed after the event, nevertheless, it is quite interesting that whole body protein turnover did not appear to be markedly depressed, despite the fact that these people were in marked energy deficits, (much more than I imagine any scientist would ever get permission to induce under these circumstances). Presumably, protein balance was maintained because the subjects were taking in a fair amount of nitrogen; I cannot remember exactly how much. But they were also exercising at these very high rates.
So the idea that exercise was somehow making protein utilization more efficient, I think, is borne out by that kind of study.