Children's sweet tooth explained

By Victoria Gill
Science reporter, BBC News

Children appear to love sugar more when they are growing faster

A compulsion for sweets is a well-known part of childhood, and research could have now explained why children love sugar quite so much.

The study, carried out in the US, found a direct link between children's growth and their preference for sugary drinks.

It showed that youngsters who preferred the sweetest drinks were the ones that were growing the fastest.

Researchers from the University of Washington and Monell Chemical Senses Center collaborated on the work.

The team used what they described as a "sip and spit" method to test the children's preference for sugary drinks.

''Kids love sweets; they'll put sugar on frosted flakes. But that love seems to decline with age," said Susan Coldwell from the University of Washington, who led the study.

"We wanted to see what was going on as that shift happens - at around the age of 16."

More than 140 11-15 year-olds took part in the test. They were given six drinks to taste, each containing an increasing concentration of sugar.

The researchers asked the children to rate, on a scale of one to five, how much they liked the taste of each drink.

"Based on those taste tests, we divided the kids into a 'high preference' and a 'low preference' group," Professor Coldwell explained.

The scientists then tested urine samples from the children for a chemical associated with bone growth in children and adolescents.

"We tested for a [breakdown product] of bone," said professor Coldwell.

"It's found in the urine either when bones are growing or in older people with osteoporosis, when their bones are being destroyed."

Children with a high preference for sugar also had higher levels of this chemical.

"This gives us the first link between sweet preference and biological need," said Danielle Reed, a researcher from Monell, and one of the study's authors.

"When markers of bone growth decline as children age, so does their preference for highly sweet solutions."