一生中最易发胖的时期

Puberty

青春期

Why? Girls naturally gain weight at this stage because fat cells increase in size and number, says Dr Marilyn Glenville, nutritional expert and bestselling author of Fat Around the Middle.

为什么？女生在这一阶段会自然增重，因为脂肪细胞的尺寸和数量会在这一阶段增大，营养专家和畅销书《腹部脂肪》（Fat Around the Middle）的作者玛莉琳·格伦威尔博士说道。

Puberty creates changes in body shape and periods don't start until there is enough body fat in place. Teenagers also need more calories than adults to supply the energy they require for growth and shouldn't be alarmed about putting on weight.

青春期会带来体型变化，直到体内有足够的脂肪时，大姨妈才会到来。青少年比成年人所需的热量更多，以提供成长所需的能量。此外，青少年不应为体重增长而烦忧。

Combat it: Don't worry. Social pressure and media images don't help but weight gain at this time is perfectly natural. Faddy and very low-calorie diets send the body into counter-productive starvation mode, reducing its metabolic rate and increasing its fat store, explains Dr Glenville.

如何击败：别担心，社会压力和媒体形象无济于事，因为青春期增重是非常自然的。格伦威尔博士解释道，过分挑食和超低热量的饮食会使身体进入适得其反的饥饿模式，降低新陈代谢的速率、增加脂肪的存储。

Dr Sally Norton, an NHS weight-loss consultant surgeon and founder of vavistalife.com, says we must lead by example. If you obsess about your weight, embark on fad diets and describe foods as good and bad, your children will copy you.

英国国民健康体系的减肥顾问外科医生和vavistalife.com的创始人萨莉·诺顿博士说道，我们必须以身作则。如果你痴迷于自己的体重，开始挑食，认为食物有好有坏，那你的孩子也会模仿你。

Leaving home/ starting university

离家/上大学

Why? A culture of stress, drinking and unhealthy eating means eight in 10 students gain weight during their time at university, according to a recent survey. "The combination of being able to eat what you want, when you want, managing a budget and newfound freedom, means many young people eat a poor diet, drink too much alcohol and don't get enough sleep," explains Dr Norton.

为什么？近期的一项调查显示，压力、饮酒和不健康的饮食文化意味着十分之八的大学生会增重。"既能随时吃自己想吃的东西、又能管理预算、还可获得自由，这意味着很多年轻人的饮食习惯差、饮酒过多、睡眠不足，"诺顿博士说道。

Combat it: Teach your teenagers basic cooking skills before they leave home, she advises. Worryingly, a Sainsbury's survey showed that more than a third of students can't even boil an egg! "Show how it's possible to eat healthily on a budget. And encourage them to sign up to societies that involve team sports and activities during Freshers' Week."

如何击败：在孩子离家前，教授他们一些基本的烹饪技巧，她建议道。令人担忧的是，塞恩斯伯里的一项调查显示，三分之一以上的学生甚至不会煮鸡蛋！"向他们展示，如何在预算内吃得健康。鼓励他们在新生周报名涉及团队运动和活动的社团。"

Pregnancy

孕期

Why? The average mother-to-be puts on a perfectly normal 10kg during pregnancy "although all women are different and some gain more," adds Dr Norton. As well as the baby, placenta and amniotic fluid, that weight includes an extra two litres of blood and fat reserves for energy and breastfeeding.

为什么？平均而言，每位准妈妈会在孕期增重10公斤，"尽管所有的女性不尽相同，且有些女性可能会增重更多，"诺顿博士补充道。除婴儿，胎盘和羊水外，增加的重量还包括额外的2升血液和用于提供能量和母乳喂养的储存脂肪。