Sex differences in response to food deprivation

Question

This question was inspired by a casual conversation with friends the other night. Some of us had noted that women tend to eat smaller meals more often (snacks, fruits etc) while men eat larger portions more infrequently. Also, several of the women said to be sensitive to food withdrawal, getting very hungry after a few hours and experiencing low blood sugar symptoms (even fainting in one case) if not eating regularly, for example if skipping lunch. Men (including myself) seemed to be less affected, often skipping meals without noticing.

This was a highly unscientific investigation with a tiny sample size :) just based on our personal stories and friends we know. It could, of course, reflect attitude/perception/habits rather than actual biological differences. It should also be said that not everybody agreed -- some men also stated that they felt sensitive to food withdrawal. But there are of course known differences in metabolism between the sexes, so it doesn't seem entirely implausible. It might also be related to different body mass, muscle mass, etc.

So my question: is there any scientific evidence that women and men react differently to short-term food withdrawal? Here short-term would be, say, up to 24 hours, as when skipping breakfast and/or lunch. Are there any data on differences in blood glucose levels after food withdrawal, for example?

Answer 1

There are very few studies about the gender-based differences in response to food deprivation in humans (or at least I didn't find many such reports).

In one of the papers, Sodersten et al conducted a research on 30 (17 women and 13 men) high school-aged subjects. After a short-term fast (skipping 2 successive meals), males consumed much more food while women actually ate less, when compared with their respective baseline quantity of meal. They suggested an inherent difficulty for women to compensate a period of fasting by increasing their food intake. They, thus, concluded that fasting might be more risky for women than men as this may start them down a self-sustaining pattern of reduced calorie intake. You can see the reference from Yamada's Textbook of Gastroenterology.

In another study, Soeters et al, 2007 showed that after a period of fasting for 38 hours, women had low plasma glucose levels than men, although they have higher amount of free fatty acids in plasma. They suggest that women are somehow protected from free fatty acid-induced insulin resistance, probably because they prevent myocellular accumulation of ceramide.

A yet another study, by Wu et al, 2011, touches upon the point that the relation between kilojoules consumed and kilojoules utilized is different in men and women. They also state that women consume less kilojoules per kilogram lean mass and store more fats in their body, especially during gestation period, as compared to men (I'm obviously not comparing the gestation period). This finding can, in a way, support the observations by Sodersten et al (see first paragraph).

If you want a more detailed report, you can have a look at this report from United Nations University (old website) by Sara R. Millman and Laurie F. DeRose. They discuss in detail why and how women and children are considered the vulnerable groups in times of long-term food deprivation since they are more likely to express hunger and have more serious probable consequences of hunger in times of food scarcity.

If you can expand your terms a little bit, there are (comparatively) many such studies on rats and other animals. For example, Sarookhani et al, 2014 measure the effects of food deprivation on formalin-induced nociceptive behaviors and $\beta$-endorphin and testosterone concentration in rats. You can find many such studies quite easily. However, I'll keep searching and adding more related studies on humans here.

Answer 2

There is a big body of literature in one specific instance of fasting: Ramadan. While not as nicely controlled as most fasting studies there certainly have been a lot of parameters investigated and if there are any differences between men and women.

A quick Google scholar search unearthed this article by Finch et al. with the following in the abstract:

Rated hunger increased substantially during the daily fast, and hunger was higher for the women than the men during the earlier days of Ramadan, whereas later, on average, fasting levels of hunger were very similar for both sexes

But I agree with Jeppe Nielsen, you will have to do a long thorough meta-analysis to come up with solid statements, sample size appear rather small.