Scientists from the University of Washington and Monell Chemical Senses Center found that children who liked the sweetest products were growing the fastest.
“This gives us the first link between sweet preference and biological need,” said Monell geneticist Danielle Reed, one of the study authors.
She added that the relationship between sweet preference and growth makes "intuitive sense" because when growth is rapid, caloric demands increase.
Children, spanning all cultures, appear to prefer higher levels of sweetness in their foods compared to adults, a pattern that declines during adolescence. The preference may motivate children, and their parents, to purchase from the sweet shelves.
And while pressure continues on the food industry to help address soaring childhood obesity rates through low-sugar confectionery formulations, this latest study suggests the biological need is innate, and more powerful than the rational. If this is the case, arguably, a responsible food industry must continue to design sweet solutions that meet the desire for sweetness but with a low-sugar profile.
The American researchers set out to explore the 'biological underpinnings of the shift' that occurs when the desire for sweet drinks and foods starts to tail off, through a study of 143 children between the ages of 11 and 15.
"Children are programmed to like sweet taste because it fills a biological need by pushing them towards energy sources,” explained Monell.
Their findings, published in the March 18 journal Physiology & Behavior, further suggest that when growth rates taper off so does the individual's desire for sweet food and drinks.
"Sweet preferences decline as children’s physical growth slows and eventually stops," commented the researchers.
The sugary solution study
Reed and University of Washington researcher Susan Coldwell investigated sweet preference and biological measures of growth and physical maturation for the 143 children.
Using a 'sip and spit' methodology, the kids 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 the results of these sensory taste tests, children were classified according to their sweet taste preference into a ‘high preference’ (88 children) or ‘low preference’ (53 children) group.
The scientists then tested urine samples from the children for a biomarker (type I collagen cross-linked N-teleopeptides; NTx) associated with bone growth in children and adolescents.
The researchers discovered that children in the ‘low preference’ group also had lower levels of the bone growth biomarker.
“When markers of bone growth decline as children age, so does their preference for highly sweet solutions,” commented Reed.
Other biological factors associated with adolescence, such as puberty or sex hormone levels, were not associated with sweet preference.
The next step
Armed with the findings that sweet preference appears to be related to physical growth, the next step is to identify the "growth-related factor that is signaling the brain to influence sweet preference”, said study lead author Professor Coldwell, at the University of Washington school of dentistry.
Source: Physiology & Behavior Volume 96, Issues 4-5, 23 March 2009, Pages 574-580"A marker of growth differs between adolescents with high vs. low sugar preference " Authors: S E. Coldwell, T K. Oswald, Danielle R. Reed