Talking about dental health with children and parents -- about what is healthy and unhealthy for your teeth -- can be one way to prevent children from developing overweight. This is suggested in a thesis from Sahlgrenska Academy, Sweden, on children's diet, BMI and well-being.

"Weight can be a sensitive subject, but if you talk about eating behaviors alongside dental health, you're looking at the issue from a different angle," confirms Louise Arvidsson, registered dietitian and PhD student at the Institute of Medicine.

In one of her sub-studies, she reviewed eating behavior, BMI and dental health of 271 pre-school and primary school children in Sweden. The children's height, weight, and food intake over one day were compared with the prevalence of cariogenic microorganisms in saliva -- and the link was clear: The children who had higher amount of caries bacteria also had significantly higher BMI and worse eating habits. They ate more frequently and consumed more foods rich in sugar.

"There is absolutely a possibility to catch these children and talk about food habits, specifically in Sweden where the dentists meets with them at an early age, but this needs a good level of collaboration between the general dentistry, the child health care and schools," says Louise Arvidsson.

With good food comes increased self-esteem, better relationships with friends and fewer emotional problems, Louise confirms in a different sub-study. Children that to a higher extent followed general dietary recommendations -- wholegrain products, 400-500 grams of fruit and vegetables per day, fish two to three times a week and a low intake of sugar and saturated fat -- reported better mental well-being.

The effects were achieved regardless of socio-economic background, and regardless of the children's weight. Her research further shows that good self-esteem could be linked to the healthier eating habits, two years later. A healthy diet and mental well-being might therefore be considered to interact, in a positive spiral.

"We know that adults with depression feel better if, in addition to other treatment, they also meet with a dietitian. The question is whether a healthy diet can have effect also in young children. There has been a lot of focus on physical activity and mental health in children, but diet is an increasingly recognized aspect," says Louise Arvidsson.

The entire thesis is based on data from a large European study, Idefics (with the University of Gothenburg having primary responsibility for Sweden's participation), the aim of which is to document and prevent childhood obesity.

In her thesis, Louise has also highlighted what does not work in protecting children from becoming overweight. Children between the age of 2-10 who were stopped from eating by their parents were generally overweight 5-6 years later.

"It clearly doesn't work, stopping your child from eating too much, or putting them on a diet, as some people were convinced. You really have to look at other methods to control a child's eating habits," says Arvidsson.

"Are you offering carrots as snacks, or both carrots and biscuits? What you eat at home is a very important question, and that you yourself try to make healthy choices. Children do as we do, not as we say."