HAN Longwei, a Junior 2 student at Jinan No 1 Middle School in Shandong, faces a challenge (挑战)every day. A McDonald's restaurant has opened near his house. It's a great temptation (诱惑) because he loves hamburgers.

"I love fast food, so I want to go into McDonald's as I pass it by," he said.

Han Longwei is 1.57 metres tall and weighs 80 kilograms. He is just one of the many overweight students in China.

A new Ministry of Education (教育部)report says about half of middle school students do not weigh a normal amount. The number of overweight middle school students has increased to nearly 24 per cent. "Obesity (过度肥胖) may become a new student killer," said Liao Wenke, a ministry official.

Why have so many students started to become overweight?

Han is like many teens his age. He spends too little time exercising and too much time playing on his computer, watching TV and, of course, eating fast food.

Students often watch many advertisements (广告) on TV which make unhealthy food look delicious. Many students are crazy about snack food (快餐) such as fried chicken, hamburgers and coke. This type of food is very bad for you and makes you fat.

Not exercising enough and spending too much time watching TV are the other two main reasons why students are getting fatter. Students have to spend a long time studying and this makes it difficult for them to find time to exercise. The Ministry of Education report shows that middle school students spend about 10 hours a day sitting down and more than 13 hours each week watching TV.

What can happen to your health if you eat too much fatty food?

Eating too much fatty foods can make your body produce a lot of cholesterol (胆固醇). Too much cholesterol can cause serious health problems such as heart disease and some kinds of cancer (癌症).

Han Longwei would like to lose weight but finds it difficult. His father said that Han doesn't like to do certain sports. "Because he is fat, his classmates often laugh at him," he said. Han is going to try and stop going to McDonald's.

"I want to lose weight to improve my health," he said. "I just wish I didn't like the taste so much!"