A diet high in meat may put girls at higher risk of breast cancer and heart disease by bringing on early puberty, according to scientists。

科学家们说，吃高脂肪肉的女孩类会使她们青春期提前，而且患上乳腺癌和心脏病的危险性加大。

A study of 3,000 girls found that girls with higher intakes¹ of meat and protein were more likely to have started their periods by the time they were 12 and a half。

一项对3000个女孩的研究发现女孩摄入太多的肉类和蛋白质很可能会在12岁或12岁半时就开始青春期。

Girls who start puberty early are believed to be at higher risk of a number of diseases - including breast cancer, ovarian cancer and heart disease。

而青春期提前会使女孩面临一系列的疾病，包括乳腺癌，卵巢癌，和心脏病。

The average age at which girls start puberty fell dramatically over the 20th century: While the average is now 12, although the average is now levelling off。

自从20世纪以来女孩青春期开始的平均年纪极度下降。而现在的平均年纪是12岁，虽然这个平均值仍然平稳。

Obesity² is also a factor in the declining average age, but it could not be the only one because the average age was now no longer falling even though child obesity was on the rise。

过度肥胖也是平均年龄下降的一个因素。但是并是是唯一的原因，因为平均年龄现在不再下降了，但是儿童肥胖仍然在持续增长。

Early periods could be linked with breast cancer - possibly because women are exposed to higher levels of oestrogen over their lifetime。

青春期提前和乳腺癌有关系，也很可能是因为女性在一生中有着很高水平的雌激素。