Fructose, used in the manufacture of many processed foods, is adding to obesity rates by increasing people's appetites, according to a new study.

The research shows that that fructose, used as a sweetener in many foods and drinks, can be more harmful than other sugar types such as glucose.

High-fructose corn syrup is used extensively in processed food manufacturing.

A US study showed that fructose failed to produce feelings of satiety and fullness, whereas glucose did.

Researchers at Yale University examined the link between fructose and weight gain.

Twenty people had two MRI scans after drinking fructose or glucose.

The researchers then measured changes in blood flow to a region of the brain called the hypothalamus, which governs appetite, after each drink.

The researchers found that glucose, but not fructose, reduced the activation of the brain regions that regulate appetite, motivation, and reward processing. They believe fructose can increase food-seeking behaviour and food intake.

The research was published in the Journal of the American Medical Association.