Nutrition intervention, especially at kindergarten and primary schools, is taking an important role in managing the increasing rates of obesity in children in Vietnam .

The obesity rate, especially in large cities like Hanoi and HCM City , will have serious social and economic consequences if preventive methods are not deployed, according to Dr Do Thi Ngoc Diep, head of the HCM City Nutrition Centre.

In HCM City , the rate of children under five who are either obese or overweight in 2010 was nearly 11 percent, rising from 3.2 percent in 2000.

The obesity rate among primary school students increased from 19.8 percent in 2000 to 38.5 percent in 2009, and 22.5 percent in 2009 from 8.1 percent in 2000 for junior-high school students. Most of them live in the city's urban areas.

Children are eating too much and not physically active, Diep said, adding that their diets contain more fat and protein, but fewer vegetables and fruit.

A study on obesity conducted among 759 junior high students in the city's urban districts from 2004 to 2009 showed the amount of time devoted to physical activities fell to 60 minutes from 80 per day.

The time they spent playing games, watching TV and learning extra subjects increased from 120 minutes to 210 minutes per day.

Obese children are at a high risk of getting hypertension and diabetes when they became adults, which could influence the growth and intelligence as well as reduce the quality of their life, Diep said.

Before the situation worsens, the education and training department must cooperate with the City Nutrition Centre, she added.

The Department of Education and Training's report showed that more than 500,000 out of 1.5 million students ate lunch at school.

At least 905 of 1,200 day-boarding schools have canteens, and the remaining schools order meals from food-processing facilities.

Inspections made by the centre and the department's inspectorate showed that lunches at schools were high in fat and lacked vegetables and fruit, and micronutrients like iodine, Vitamin B and calcium.

Diep said schools must adjust their menus and include healthy meals. Time for physical activities should also be increased, she added.

Since 2008, the centre has been working with the city's Department of Education and Training to carry out a project on nutrition intervention and increasing physical activities to prevent obesity.

It has been expanded from two to four schools, and will be implemented in more schools.

After the programme began, the obesity rate and the number of children who were overweight fell by 20 percent, she said.

Teachers should be trained in nutritional knowledge, particularly those who showed an interest. They must impart this to the students, she said.

At a recent workshop, Dr Nguyen Tai Dung, deputy head of the Department of Education and Training's Students Affair Office, announced that the department had set up a school health-steering board.

The department has given priority to obesity prevention and management at kindergartens, he said.

Many kindergarten education offices under the department have developed several measures to prevent obesity.

Do Thi Dien, principal of Tuoi Tho Kindergarten No8 in District 3, said that her kindergarten gives regular health check-ups to children as well as guidance to parents about obesity prevention.

Teachers and caretakers at her kindergarten have been trained in these activities.

Bui Thi Ngoc Ha, principal of Kindergarten No4 in District 3, said that her school has carried out similar activities.

The kindergarten also encourages parents to let obese kids attend eurythmics or swimming courses, and at the same time works with the city's nutrition department to offer nutritious meals for kids.

The results was a drop in the rate of obesity and overweight children, from 26,000 cases at the beginning of last school year to 17,893 at the school year-end, according to the Kindergarten Education Office's report./.