睡眠--睡眠太少使胃口大增

 

药物--很多现代药物会导致体重增加<

 

母亲的年龄--年龄偏大的女性易生出肥胖的孩子

 

择偶--肥胖者之间容易结为伴侣，这会导致他们的孩子肥胖

 

供暖和空调--舒适的温度会阻碍体内脂肪的燃烧

 

基因--体型一部分由遗传因素决定

 

戒烟--尼古丁能抑制食欲

 

人造化学物质--有些化学物质会影响体内控制脂肪水平的激素

 

出生时的体重--体重不足的婴儿变肥胖的可能性较大

 

年龄增长--体重随着年龄的增长而增加

Eat less and exercise more - it has long been the mantra for shedding those extra pounds. But now it seems that all the hard work may have been in vain.

 

Scientists say there are ten other reasons why people just keep getting bigger. They claim that sleeping habits, central heating, medicines and even some pollutants can play a role in weight gain.

 

Traditionally, health practitioners have focused on diet and exercise - and a large dose of willpower - to treat the problem.

 

However the scientists from top U.S. and Canadian universities say that these other factors must be considered.

 

Lack of sleep could be partly to blame. In recent years, the average night's sleep has dropped from nine hours to just seven.

 

Sleep deprivation alters levels of the hormones that regulate food intake and body fat and increase hunger and appetite.

 

If it is too hot or too cold, we burn calories to cool down or heat up. But if the temperature is just right, the calories may be turned into body fat instead.