Cyclical low carb diets and a woman's hormonal response - can't find anything

[JJFigure]

Well, I've been on a quest to see if cyclical low carb diets have any anabolic effects on women, and can't find anything. A friend and I have been searching through medline and sportsdiscus, and can't come up with anything specific to women and their hormonal response (GH/testosterone/estrogen) to this type of diet - or any diet, for that matter. However, we keep running across references that women use fat more efficiently as fuel than men do - that's about the only thing I can find in support of a cyclical high fat/low carb diet for women.

Has anyone else ever run across any studies specific to women? I've emailed Dr. DiPasquale and Rob Faigin, but neither of them have replied.

 

[MS]

"women use fat more efficiently as fuel than men do"

Translated as we tend to be more fat-assed than males no matter what we eat LOL.

I don't think you'll ever find any scientific literature specific to women and CKD!!! But as I said before, it seems pretty certain to my mind that a diet that theoretically increases gonadal testosterone production in men would most likely lead to an increase in gonadal estrogen in women. This is not necessarily a bad thing, and to sum up just one of many pieces of research and thinking in this area, Campbell et al (Curr Opin Clin Nutr Metab Care 2001 Nov;4(6):515-20) say this "...........It appears, therefore, that estrogen increases the metabolic capacity for both carbohydrate and
lipid metabolism, perhaps increasing the overall metabolic flexibility of skeletal muscle. Conversely, progesterone negates both these
effects, and could therefore result in a state of relative metabolic inflexibility, similar to that observed in the metabolic syndrome."

And as D'Eon, et al (Am J Physiol Endocrinol Metab 2002 Nov;283(5):E1046-55) point out, "……………The data suggest that estrogen lowers carbohydrate oxidation by reducing estimated muscle glycogen utilization and glucose rate of disappearance. Progesterone increases estimated muscle glycogen utilization but not glucose rate of disappearance. The opposing actions of estrogen and progesterone on estimated muscle glycogen utilization may be mediated by their impact on free fatty acid availability OR VICE VERSA."

None of this answers your diet question, but should reassure you that estrogen is not ALL bad news. On the diet front there is also reasons to think that men and women will respond differently to varying macronutrients. For instance, Kratz e tal (J Clin Endocrinol Metab 2002 Nov;87(11):5008-14) conclude " .........Thus, it is proposed that serum leptin levels were affected by the high amount of alpha-linolenic acid in rapeseed oil. However, questions remain as to why this diet differently affected serum leptin in men and women." This was in response to their finding that the rapeseed oil intervention group of women (but not men) showed a dramatic reduction in leptin levels compared to pre-diet levels. Also, as you prolly know, women enter ketosis more rapidly and more deeply than men thanks to their hormonal environment. This is in spite of women tending to be more insulin resistant (for the same bodyfat) than men. Also keep in mind your statement "women use fat more efficiently as fuel than men do" is not just about burning fats versus carbs, but "efficient" in this context also may mean that a female may have a lower BMR on a high fat diet. And if that's not enough, you will find most women will also be more insulin resistant during the carb-up period of a cyclical diet, meaning more bloating/fluid retention and less efficient reglycogentaion of the muscles. ALL VERY THEORETICAL and all you can do in the real world is to try it and compare it to other diets. Everyone is different, and when it comes to hormones it is even more true that every women is even MORE different. A LOT of women have noted what feels like the emergence of an eating disorder when discontinuing CKDs. This almost certainly has a lot to do with large swings in estrogen levels that all by themself can trigger eating disorders.

This lengthy reply was designed to confuse you as much as help you, but more importantly to illustrate how truly complicated women are!

 

[JJFigure]

Thanks MS! Wouldn't it be nice, though, if a few more studies were done using female athletes as subjects?

That's pretty much what I concluded - just keep playing with the diet until you find something that works for you. I was just annoyed I assumed Faigin and DiPasquale's claims that this type of diet is anabolic meant it was anabolic for men AND women. Have to remember that saying about making assumptions...