WHITE bread, candies, potato chips, soft drinks and carton drinks with large doses of white sugar and chemicals are the most popular food items being sold in tuck shops. A survey conducted by Green Power shows that tuck shops and canteens occupy an important position in a student's school life. The study, the Green Power's first Green Consumer Survey, involved over 600 students, teachers, headmasters, parents, medical professionals and government officials. Among the students interviewed by telephone, half said they bought food/drink from tuck shops - nearly all junk food. Boys outnumber girls in soft drinks consumption by three to one, and noodles by two to one. Girls, on the other hand, eat four times more ice-cream than boys. Generally speaking, boys patronise tuck shops more than girls. Lower form students do so more than their seniors, and the former have less healthy eating habits. Those from lower-income families have less healthy eating habits. Girls are more positive than boys about buying ''greener'' foods and drinks if given a choice, and so are the upper form students when compared to juniors. The same is true of students with more money to spend. If given a choice, 68.3 per cent of the interviewees said they would consider buying soyabean milk or fresh fruit juice. The study paints a rather gloomy picture. As a result, Green Power recommends the introduction of fresh fruit, real fruit juices, homemade soyabean milk, chrysanthemum tea, salads, nuts, sweet corn, pop corn, high-fibre biscuits, whole wheat bread, yoghurt and vegetarian noodles in tuck shops. It also urges school authorities to discourage the sale and consumption of soft drinks, potato chips, fish balls, candies, chicken wings and drumsticks, sausages, ice-cream and hot dogs. The medical adviser to the project and Green Power activator, Dr Sandra Leung Tuk-kwan, said a lot needed to be done, and urgently, in order to save children from permanent damage resulting from such horrifying diet. ''The excessive sugar, oil and salt will ensure they grow up full of health problems, while the artificial chemical additives could bring about behavioural problems like hyperactivity and agressiveness,'' she said.