The Biology of . . . Sex Ratios | Sex & Reproduction | DISCOVER Magazine
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"Similarly, in countries at war, sex ratios tilt toward boys, presumably because of frequent sex during home leaves and after demobilization."
This is NOT true across the board, as WW1 in Western Europe decreased the sex ratio, as well as in the Soviet Union after WW2. I read a interesting study about the increase in the sex ratio after WW2 in the US, I will have to find it because it made sense to me.
http://www.ncbi.nlm.nih.gov/pmc/arti...00572-0075.pdf
^^The war study, was not the one I was thinking of, but along the same lines. At the bottom of this one, they mention a study done by Martinez-Gustin about the relationship between the somatype of parents, expressed by the Rohrer's index and the sex ratio of offspring and I would sure like to read that one!
There are quite a few studies that seem to indicate the opposite to be true. That tells me that some other factor is coming into play and NOT "frequent sex during home leaves" (which I do NOT believe at all)Quote:
Originally Posted by harleyquinn
http://humrep.oxfordjournals.org/con.../12/3173.short
http://jech.bmj.com/content/56/8/622...e2=tf_ipsecsha
http://humrep.oxfordjournals.org/con...e2=tf_ipsecsha
Let's keep in mind this was published in 1956. Not that it's worthless, just that I put more stock into newer studies as a general rule.Quote:
Originally Posted by harleyquinn
Something interesting to consider is that if there is anything to the fertility theory, it ~may~ be that in times of stress and strife, a higher proportion of well-off and well-nourished people choose to or are able to have babies and so that skews the gender ratio towards boys. If people aren't sure where their next meal is coming from and either lose interest in sex all together, are unable to conceive/carry a baby to term due to lack of food, or decide to be extra cautious because they aren't in a good place to take care of a baby, that may actually prevent a number of girls from being conceived who otherwise would have been.
People who choose to and are able to conceive right after a war, are preselected to some extent, for being better off and probably better nourished than those who can't conceive or choose not to. The samples themselves are skewed.
^ yes
I did look into the Roher's index and it seems that has been debunked completely or else nobody cares ;)
It's funny how many studies there are out there that were just never followed up on. I always want to know why - was there some other study or discovery that debunked the original, or was it just that no one had the time or resources to continue??
Ok, this is an old topic, but recently i watched the documentary of micheal mosley. It was about how to eat to became old in a healthy way...
His conclusion was that we have to eat less overall and far less protein.
There are some studies that show that IGF-1 decines during periods of fasting.
He discovered that when he ate 600 kcal a day for just two days a week, his blood values declined to healthy levels. That's now the basis of his 'Fasting diet'; eat 500(women)/600(men) kcal a day for two days a week and the rest of the week you can pretty much eat everything you like.
Reasoning behind it being that in times food were deprived, when we were still hunters, bodies had to become in perfectly well conditions (lean and fit for running after preys), even new neurons in the brains were developed (for example to be more alert or remember where food was available), for surviving. The average age of men increased during world war, probably because of this mechanism!
Made me wonder whether swaying could result in the opposite that we want; a healthier body. But than i thought mr mosley is only anecdotical evidence and more research is needed, maybe this ain't working for women. Additionally, we eat more than 500kcals.
Bit still it's food for thought!
I personally think that's a dreadful idea that will mess up your metabolism and I do not recommend anyone do that. I think that is a misuse of data, because the human lifespan has increased due to advances in medicine and not any kind of diet during wartime.
We are not hunter/gatherers that have not eaten much since childhood and are used to that - to go from a normal diet to fasting 2 days a week is very different than a person who has lived their entire life working hard on very few calories and on occasion had to go without eating. Our metabolisms are totally different than that.
In terms of swaying, we're not talking about health, we are talking about fertility. A balanced diet with meat and fat in it has been shown to boost fertility, and a heart-healthy, cancer-preventative type of diet would sway pink regardless of whether it is good for health or not. Mice fed a very low calorie diet lived a long time, but stopped having babies. We're not after "health" altho sometimes we use that term - we're after high vs. lowered fertility.
I do think there are some women who are very heavy and may be better off for their sway if they were to hold steady where they were at and just toss the dice - but if they've already conceived boys at a heavier weight then I would still think something would need to change.
I can't directly go with you conclusion that our metabolism is totally different than 10000 years ago, simply because i'm not very into this topic. We are treating it different, but i thought that evolution took somewhat longer. The war data were used as an example by an professor in aging, and just a small part of what he tried to make clear. Seeing the documentary just made me wonder if there's any clue in there.
I totally agree with you that we (as in 'us swayers') are not looking for health, but after seeing this i thought that we may do this unconsious sometimes, which may explain part of the opposites.
Did you see the documentary he made for the bbc?
Atomic once you said too that protein is terrible for fertility. Then why should we pinkswayers limit protein ?
studies have shown that diets low in protein and fat give more females, but of course it could be low fat causing that rather than the proteinQuote:
Originally Posted by onebigwish
no actually it's meant to be VERY healthy to do this kind of diet -- not as a swaying diet I might add, but as a general lifestyle change to improve your wellbeing and future health. My husband has researched it in depth over the last couple of years and tried it out himself (a variation of a fasting diet, not a 5-2 one that has been popularised) and he has lost weight and feels healthier. My office-mate at work also does the 5-2 fasting diet. All the evidence shows that the kind of diet is linked with reduced risk of alzheimers, longer life, reduced insulin resistance and cholesterol, CURING diabetes in some people doing it, and lower risk of cancers, etc. It has an awful lot of benefits if people can stick to the rules.Quote:
Originally Posted by atomic sagebrush
I know that it's said by those who promote it, to be a healthy diet. I personally do not believe that it is healthy for people who have gone a lifetime when they were eating all day long and that is what their bodies are used to (and also what their parents and grandparents and beyond, were doing due to epigenetics possibly altering metabolism on the genetic levels by turning genes on and off during fetal development) to suddenly start fasting 2 days a week. I just don't. I'm glad it works for your husband and coworker.
Sky high protein intake such as Atkins Diet is not good for fertility. And in fact I have actually said on numerous occasions that an all-protein diet could possibly sway pink and I've seen people get girls on Atkins. I do not recommend Atkins or similar diets, however, because they are not safe pre-pregnancy and also because higher intake of saturated fats has been shown in some mammals to sway blue.Quote:
Originally Posted by onebigwish
Blue swayers do NOT eat massive amounts of protein. In fact I tell them not to eat too much protein. They eat about 90 grams of protein and they eat protein + carbs at every meal and snack.
the blood tests they have after starting it (even after a lifetime of eating all day) show good results, though
I have a friend who has been working at (what he says!) is the forefront of anti-aging science, and the research he was a part of indicated that fasting which is moderately extreme releases responses that are reparative. He explained it in much more detail than I can remember, but the scientists found that the pattern that exaggerated this effect the most was not weekly fasting, but fasting a few times a year for a few days. There was some number of days that was too many, and some that was too few for certain bodily responses to be triggered- like there was something our bodies produce only under these circumstances which actually rebuilds cells and creates new neurons... can't remember, but it was total fasting. What did your husband research?Quote:
Originally Posted by rainbowflower
People have studied the best diets for health for 100 years in huge studies and come to no consensus. There's always something scientificish behind all these various miracle diets, otherwise people wouldn't do them. This article indicates some of the problems with the data and also that the diet seems to affect women differently.Caveman fasting diet may leave women diabetic | Health | Life & Style | Daily Express There's also a much higher rate of gallstones with this fasting diet and women being much more likely to have gallstones during pregnancy, it is ill-advised to do anything to increase the possibility.
The job that I have to do here is keeping people fertile, healthy, and sane while doing gender swaying (successfully). It has nothing to do with overall health or longetivity (which I think the data is inconclusive anyway). I don't think that for the average gal in her childbearing years planning a pregnancy, this is in ANY way a good or healthy thing to do and this is clearly demonstrated by the number of people who set off doing LE Diet overly strictly and then stop ovulating within only a couple months. The VCL diets were also hugely touted to be so "good for health" and yet they drastically reduced fertility at the same time and then it turned out that people and animals who were doing some of those diets had a higher rate of death of other causes anyway. And there will be some people who decide to try it all and fast on top of drastically reducing sodium, potassium, and overall nutrient content and that is going to kill someone.
Aside from all that, most people are not going to be able to stick to a diet like that and for gender swaying, I think it's worse than nothing because your body will be encouraged to hang onto every morsel you eat on the days you are not fasting. Plus, the level of commitment and obsessing over food that such a thing requires, is going to send T levels up, up, up anyway.