Researchers from the University of Florida found when they analyzed the dieting and smoking habits of 7,795 teenagers that dieting did not effect boys in the same way.

The study ™s lead author assistant professor Mildred Maldonado-Molina says dieting was a significant predictor of the start of regular smoking among females.

Dr. Molina says the results were not unexpected as it is well known that nicotine can suppress the appetite.

The researchers used data from the National Longitudinal Study of Adolescent Health, a school-based study of health-related behaviors among girls and boys in grades 7 through to 12 in the U.S.

Among the teenage boys, those who tried dieting but did not stick to it, were the ones at risk for taking up smoking and while more boys were overweight only about a quarter were dieters, and just 12 percent were consistent dieters.

According to the Centers for Disease Control and Prevention (CDC) the percentage of teenage smokers has dropped since the survey was performed.

The CDC says in 1995, about 35 percent of high school students smoked regularly, while currently about 23 percent of high school students and 8 percent of middle school students reportedly smoke.

According to a 2006 CDC report on tobacco use among youth, the percentage of girls who smoke is slightly higher in both age groups.

Research demonstrates that both girls and boys are more likely to become regular smokers if cigarettes are available in the home.

The study is published in the American Journal of Health Promotion.

Rosemary Hignett, head of nutrition at the FSA says consumers ought to know the proportions of each food group needed for a healthy balanced diet.

Hignett says the advice is not a '10-minute fad' but rather a diet for life which will help reduce the number of diet-related illnesses such as heart disease, stroke, diabetes and some cancers.

Potatoes do not count towards the target "five a day" portions of fruit and vegetables, says the FSA, but baked beans do.

According to the FSA a healthy, balanced diet should be made up of around one third fruit and vegetables, one third bread, rice, potatoes, pasta and other starchy foods, 15% milk and dairy foods, 12% meat, fish, eggs, beans and other non-dairy sources of protein and just 8% food and drink high in fat or sugar and no more than 6gms of salt a day.

The new image will be used by dieticians, nutritionists and the National Institute of Health and Clinical Excellence.