Children who regularly sit down to family meals and get plenty of vegetables in their diet tend to be thinner than their peers without such eating habits, a new study finds.

The results, published in the Journal of Pediatrics, may not sound surprising. However, few studies have looked at the relationship between children's weight and their diet patterns — which are more complex than, for example, sugar or fat intake.

And while it is generally believed that sitting down to family dinner is good for kids, there has been little research evidence that doing so actually helps keep children slim.

For the new study, Greek researchers interviewed 1,138 children ages 9 to 13 about their diets and physical activities, and used that information to identify five general diet-and-lifestyle patterns across the group.

One was what they dubbed the "dinner, cooked meals and vegetables" pattern. Children with this pattern had a high intake of vegetables, regularly sat down to family dinner and typically had traditional "cooked" meals (hot or cold) for lunch and dinner, rather than sandwiches, snack foods or "breakfast-like" meals.

Kids who fell into that pattern generally had a lower body mass index, or BMI — a standard measure of weight in relation to height used to gauge how fat or thin a person is. They also had smaller waistlines and less body fat than their peers who did not fit the diet pattern.

None of the other four diet-and-lifestyle patterns the researchers identified were associated with children's weight or body-fat levels.

Those patterns included an "unstructured eating, fast food/sugary foods and sedentary lifestyle" pattern, and "high fiber," "breakfast," and "exercise, fruits and vegetables" patterns.

It is not clear why those four categories failed to show a link to children's weight, while the family meal/vegetable pattern did, according to the researchers, led by Dr. Mary Yannakoulia of Harokopio University in Athens.

But, they write, the habits of sitting down to family dinner and having cooked meals could signify children who are closely sticking to the traditional Mediterranean diet — one rich in vegetables, olive oil, whole grains and fish.

A key limitation of the study is that it assessed children at one time point. Only a study that follows children over time can show whether those who follow a family meal/vegetable-type pattern are less likely to become overweight.

However, Yannakoulia and her colleagues write, the findings suggest that such an eating pattern stands as a "potential preventive approach" to combating childhood obesity. They note that it is also a "non-restrictive" way of eating that most children can live with.