求以my opinion on going on a diet为题的英语作文?

Diet and Health（饮食与健康）可以参考：
A study done in Greece says people can live longer and healthier lives if they eat what is known as the Mediterranean diet.Foods included in this way of eating are vegetables,fruit,beans,fish,whole grains and olive oil.Such a diet generally gets about forty percent of its calories from olive oil and other fats that are considered healthy.
Researchers from the University of Athens and Harvard University Medical School in Boston,Massachusetts did the study.They published the results in the New England Journal of Medicine.
The study involved twenty-two-thousand healthy people in Greece.They were between the ages of twenty and eighty-six.The researchers questioned each of them about what they ate and how much they took part in physical activity.
The researchers gave them points for exercise and for each part of the Mediterranean diet they followed.People who ate vegetables,beans,fruit,nuts,whole grains and fish got higher numbers than people who did not eat these foods.
People also received a point for drinking some alcohol -- about one glass of wine a day for women,two glasses for men.They got no points if they drank more or less than that.
The study lasted for a period of four years.During that time,two-hundred-seventy-five people died.Thirty-five percent of those people died of cancer.Twenty percent died of heart disease.
The researchers found that those who followed the Mediterranean diet were less likely to diethan those who did not.Also,the followers of the Mediterranean diet were less likely to die of heart disease and cancer.And the study showed exercise to be important.The people who exercised at least one hour a day had a twenty-eight percent less chance of dying than those who did not exercise.
The study also showed a link between following the Mediterranean diet and living to an old age.And it confirmed earlier studies that had suggested the effectiveness of such a diet.
Researchers say it is not just one or two foods in the Mediterranean diet that make the difference -- it is all the foods together.So they say people should eat a lot of fruits,vegetables,beans and fish.They should use olive oil in their cooking.And they should exercise every day.