Women could increase their chances of conceiving a baby boy by upping their calorie intake when trying to get pregnant, research revealed yesterday.
Eating a daily bowl of cereal was also linked to having sons.
The study found that women with the highest calorie intake before conception were more likely to conceive a baby boy than women with a lighter diet.
The researchers, from Oxford and Exeter universities, said the results suggested that the dieting habits of women in the western world could help explain the falling male birthrate.
The latest research, published in the journal Proceedings of the Royal Society B, looked at 740 first-time mothers in the UK.
The women were asked to keep records of their eating habits before and during the early stages of pregnancy.
The study revealed that 56 per cent of women who ate more than 2,200 calories a day before conception had a boy, compared with 45 per cent of women who ate less than 1,850 calories.
The researchers found that 59 per cent of women who had cereal every day had a son, compared with 43 per cent of those who had less than one bowl a week.
Women with sons also had higher levels of nutrients in their diets, such as potassium, calcium and vitamins C, E and B12.
Over 40 years there has been a consistent decline in the proportion of boys being born in western countries – a drop of about one per 1,000 births annually.
Dr Fiona Mathews, one of the researchers from Exeter University, said: “This research may help to explain why in developed countries, where many young women choose to have low- calorie diets, the proportion of boys born is falling.”
IVF research suggests that high levels of glucose encourage the growth of male embryos, while inhibiting female ones.
In humans, skipping breakfast depresses glucose levels and so may be interpreted by the body as indicating poor conditions and low food availability.
Dr Mathews said having a boy was also linked to higher levels of potassium – which could amount to as little as an extra banana a day before conception.
Higher levels of salt were also consumed by those having boys, though the researcher warned that eating large amounts of salty food could raise blood pressure.
“We could say that if you increase your calorie intake slightly while trying to conceive you may be flipping the odds of you having a boy slightly in your favour,” Dr Mathews said.
Bridget Aisbitt, of the British Nutrition Foundation, said there were no specific recommendations for diet prior to conceiving, apart from taking folic acid supplements to prevent spina bifida.
Professor Stuart West, from Edinburgh University, cautioned against using diet to try to influence the sex of a child.
“First, the effect appears to be relatively small, with the sex ratio varying from only 45 per cent sons with low-calorie diets, to 56 per cent sons with high quality diets,” he said.
“Second, similar data in animals such as non-human primates shows huge variation between studies, and so it would be key to determine the repeatability of these results.
“Third, diet will have other effects for both the parent and offspring.”
译文:
高热量饮食帮你怀上男宝宝
昨天一项调查显示，女性如果摄入高热量食物，就能增加怀上男婴的机率。
就是吃普普通通的一碗米饭也和生儿子有关系呢。
研究表明，女性在怀孕前多吃高热量食物的话，比吃得清淡的女性更有可能怀上男婴。
来自牛津和埃克塞特大学的研究人士指出，该研究的结果可用来解释西方女性的节食习惯所导致的男婴出生率下降这一现象。
《皇家学会学报B辑》上刊登的最新研究中，对英国740位第一次做妈妈的女性们进行了调查。
这些女性被要求在自己怀孕前和怀孕早期记录自己的饮食习惯。
结果发现，准妈妈中日热量摄入量在2200卡路里以上的，有56%怀上了男孩，但摄入热量在1850卡路里以下的那部分女性中，只有45%怀上了男孩。
研究员们指出，在每天都吃谷物的准妈妈中，有59%是生男孩，但一周内吃的谷物少于一碗的那些人，则生男孩的概率只有43%。
生男孩的妈妈们，她们的饮食中营养含量相对较高，包含了像钾、钙、维他命C、E和B12等成分。
近40年来，在西方国家，男婴的出生率持续下降—平均每年下降约千分之一。
来自埃克塞特大学的费昂娜·马修斯博士指出：“这项研究可能就向我们揭示了在一些女性有节食习惯的发达国家，男婴出生比率就低的真正原因所在。”
试管受精的研究也发现，葡萄糖有益于男性胚胎的发育，而抑制女性胚胎的生长。
就人类而言，不吃早饭就会降低葡萄糖的含量，但是在人体中就体现为营养不良和食物摄入量不足。
马修斯博士说道体内钾的含量高的话也有助于提高怀男婴的机率—这可以通过在怀孕前每天多吃个香蕉从而来提高钾的含量。
而且体内盐的含量高的话，也能提高怀男婴的可能性，但是专家同时提醒大家要注意，摄入大量盐有可能导致高血压。
马修斯博士认为，“如果你因为想怀孕就吃高热量的食物的话，你就很有可能因此而怀上男婴。”
英国营养基金会的布赖甘特·爱思比特却认为，没有什么特别的饮食方式可以提高怀孕率，除了多摄入维生素B的话，能够防止婴儿患上脊柱裂病。
爱丁堡大学的斯图亚特·威斯特教授也警告人们，不要想着通过饮食来影响婴儿的性别。
“首先，即便有影响，那也是很小的，怀男婴的机率无非也就在吃得少的45%到 吃得多的56%之间。”
“其次，对除人类以外的灵长类动物的研究显示，不同的研究起结果有很大的不同，因此确定这些结果的重复概率就非常有必要了。”
“第三，饮食会对母婴产生其他各种影响。”