The public nutritionist specialty is one of the 11 new professions certified by the Ministry of Human Resources and Social Security of China. Certified nutritionists fall into three categories. "With a certificate at any level, it is easy to find a job," said Wen. Public nutritionists are currently hard to find, she said, with one to serve every 650,000 people in China.

Besides public nutritionists, there are also food, diet, clinical and sports nutritionists, Wen said.

The Chinese Cuisine Association on March 1 released China's first professional criteria to improve the nutritious value of catering services. The criteria stipulate that restaurants, dining halls and collective catering units with more than 300 seats should hire a certified full- or part-time nutritionist to analyze the menu's major ingredients and caloric content and give customers with special needs suitable nutrition suggestions. Nutritionists are also responsible for changing menus along with the seasons.

Reconsidering balance

The old school of thought had it that rich food provides rich nutrition, but science now knows that is not always the truth. Earlier this year, the Nanjing Public Nutritionist Training Center studied Nanjing residents and found that they were suffering from "implicit hunger," a health condition wherein the sufferer lacks necessary vitamins and minerals.

The local Jinling Evening News reported that Nanjing residents' diet structure is too narrow because meat takes up a large proportion of their daily caloric intake while they do not eat enough cereal or vegetables, which leads to the implicit hunger.

"Implicit hunger hides deep in our bodies. It's hard to observe it even using medical instruments," said Yang Yi, Director of the Nanjing Public Nutritionist Training Center. "By the time medical instruments can observe it, our bodies have already been seriously damaged by it."

Yang said implicit hunger has become a silent killer of human health. "One effective method to prevent implicit hunger is to diversify our diets and to keep nutrition in balance," he said.

"Balanced nutrition is an effective medicine to cure many kinds of diseases," said Liu Qingchun, a nutritionist at the Armed Police General Hospital. "If we can maintain balanced nutrition, enough sleep and an appropriate level of exercise, we can prevent today's A/H1N1 flu from becoming an epidemic."

Daily fuel

"Many common foods in daily life have abundant nutrition," said Cao Jianmin, Director of Teaching Research Office of Sports Biochemistry, Beijing Sport University. He said a potato is a good example.

Potatoes are rich in starches, which can help to balance nutrition, Cao said. A 148-gram potato can also provide 45 percent of the body's daily requirement of vitamins.

In 2000, Zhang Jian, a university teacher in Beijing, successfully swam across the Bohai Straits without any help, and was given the moniker of "China's first person to cross the straits." Cao contributed to the event by being Zhang's nutritionist. He also worked as the director of the Medical Research Committee at the China Triathlon Sports Association. "It is only by combining sports with diet nutrition organically that we can improve the health and the abilities of athletes. Some common foods including the potato can provide enough of the nutrition that athletes need," said Cao.

Besides appropriate levels of protein, fat and water, carbohydrates are also an important part of a nutritious diet. Cao said that cereals and potatoes are good sources of carbohydrates while also being low in fat. That 148-gram potato also has 26 grams of carbohydrates and only 110 calories from fats and cholesterols. It has only 21 percent of the calories compared with the same weight of rice.

Many people still think that taking in carbohydrates or eating potatoes can make people fat. "The main cause of a person growing fatter is when caloric intake surpasses the burning of calories," said Cao. "Potatoes have few calories so we don't have to worry about growing fatter when eating them.

"In fact, besides balancing nutrition and supplying energy, potatoes are outstanding at reducing weight," he said.

Besides potatoes, soy milk and vegetables are highly nutritious foods, according to Cao. "There is no division of good or bad between different kinds of foods, but there is a division between reasonable and unreasonable in choosing different kinds and amounts of foods to balance your nutrition," he said.