题目内容：

    I've been eating a high-Fat,carbohydrate(碳水化合物)-restricted diet for almost 20 years,since I started as an experiment when investigating nutrition research for the journal Science. I find if s easy for me to keep a healthy weight when I eat this way. But even after two decades, the feeling of being on the edge of a slippery slope is ever- present.

Researchers are generally divided on why we often fail to stay on diets and what causes obesity. The conventional thinking, held by the large proportion of the many researchers, is that obesity is an " energy balance" disorder,and so the treatment is to consume less energy ((fewer calories) ) and spend more. When we fail to keep this prescription, it suggests that we simply lack will power.

The minority position in this field—one that Dr. Ludwig holds, as do I after years of reporting—is that obesity is actually a hormondal(激素的)regulatory disorder, and the hormone that controls this process is insulin (胰岛 素).It signals fat cells to gather fat,while telling the other cells in our body to bum carbohydrates for fuel. By this thinking these carbohydrates, particularly grains, known as high GI carbs, as well as sugars are likely to make you fat.

"Raise insulin levels even a little" , says Dr. Robert Lustig, a professor at the University of California, San Francisco,"and the body switches over from burning fat for fuel to burning carbohydrates. Once people who are 'carboholics,' get their insulin levels down, they become less carboholic. And if they start eating carbs, they go right back to where they were before. " Researchers like Dr. Ludwig and Dr. Lustig believe that a person can minimize these carbohydrate desire by eating lots of healthful fats instead.

Finally, any successful diet is by definition a long-term commitment. If we buy into the logic of carb -restricted diets, then it implies acceptance of a lifetime restriction.

1.What does the author feel like doing according to the last sentence of the first paragraph?

A.Keeping a healthy weight. B.Sticking to a good habit.

C.Stopping nutrition research. D.Breaking a diet

2.What does the author think lead to obesity?

A.Lack of exercise. B.Taking in too many carbs.

C.Lack of will power. D.Taking in too much calorie.

3.According to the text,what would Dr. Lustig advise carbholics to do?

A.Reduce carb intake to the least. B.Consult doctors immediately.

C.Consume as much fat as possible. D.Work out regularly.

4.What is the best title of the text?

A.Why is cutting carbs so tough? B.What does a healthy diet consist of?

C.Who are to believe,the majority or the minority? D.How can we lose weight?