Eating more fibre has a big impact in trimming the waistlines of young people.

The researchers had 85 overweight Latino boys and girls (11 to 17 years old) in the US fill out a questionnaire on their eating habits, and then report on their diet again two years later. At this stage of life, the diets of some young people tend to get worse. The researchers looked at belly fat, which is the most dangerous type of body fat, as fatter waistlines increase the risk of diabetes and heart disease.

It was found that fibre intake fell by 3 grams per 1,000 calories consumed, on average, for 46 of the study participants, while it increased by the same average amount for the remaining 35. Belly fat increased 21 percent for the study participants who were eating less fibre, but the young people who upped their fibre intake had a 4 percent reduction in belly fat.

Even slight changes in dietary fibre had a significant metabolic impact. The recommended fibre intake for young people is 14 grams per 1,000 calories consumed, or about 25 to 30 grams daily.

Based on the findings, increasing fibre intake by six grams a day - the amount found in half a cup of beans - could have a significant impact on young people's belly fat. Just because it says 'whole wheat' or 'multigrain' doesn't mean it's a good source of fibre. People think if it's brown, or if it's wheat, it's good, but that may not necessarily be true. People of any age who want to boost their fibre intake need to look carefully at food labels.