Date Published: 9 June 2011
Obese people have reduced sensitivity to the sweetness of soft drinks according to recent research
Obesity has been linked to reduced sensitivity to the sweetness of soft drinks together with enhanced subconscious liking of sweet food. This follows from recent research at Bristol and Bangor universities in the UK.
A study reported by scientists at these universities has shown that overweight and obese people have a dulled sensitivity to the sweetness of soft drinks, especially sugary drinks, together with an increased subconscious liking of sweet food. Further, the results of the study indicated that even in cases of people who are not overweight, drinking two sugary drinks a day for just four weeks is sufficient to both dull sensitivity to the taste sensation, and increase preference for sweeter tastes - especially in people who did not already have a preference for sweet or sugary drinks.
There are health implications from this research because as sweet 'treat's become less rewarding, people may tend to consume increasing concentrations and quantities of sweet foods or drinks, leading to a "vicious circle" of eating sweet and high calorie foods.
Dr Lucy Donaldson at the University of Bristol's School of Physiology and Pharmacology, said:
" We have known for some time that the way that we perceive different tastes can change under different circumstances. This finding, that a couple of sweet drinks a day over a short time can dramatically change taste, was a real surprise."
Dr Hans-Peter Kubis at the University of Bangor's School of Sport, Health & Exercise Sciences, who led the study, expressed the opinion that this problem needs addressing at a national level, adding:
" My reaction would be to encourage the government to consider taxing sugar that is added to foodstuffs and have that tax ring fenced for the health budget."
The results were based on experiments carried out at Bangor University's School of Sport, Health and Exercise Science in collaboration with the University of Bristol's School of Physiology and Pharmacology.
In the trial, lean and obese people were asked to rate their perception of and enjoyment of sweet and salty tastes. The initial trial showed that overweight and obese participants actually rated identical drinks as being less sweet in their perception, than that of the lean participants. In further experiments they tested the subconscious preference for sweet food with a computer based test finding that overweight and obese participants had a stronger preference for sweet than lean. The conclusion was that overweight and obese participants had a reduced sensitivity to sweetness but an enhanced subconscious preference for sweet food.
Dr Kubis explained:
" Our subconscious drive plays a huge role in what food choices we make, and as overweight people feel hungrier they are more affected by their subconscious drive for sweet high calorie foods."
To test whether sweet food consumption may be responsible for these findings and to understand if it was possible to recreate the taste perception of obese people in normal weight people, those who do not usually consume sugary drinks were recruited for a second experiment. The researchers found that in as little as four weeks it was possible to replicate the dulling of the 'sweetness' of sugary drinks and lessen the enjoyment just by repeated consumption.
Taste perception and implicit attitude toward sweet related to body mass index and soft drink supplementation; Francesco Sartor, Lucy F Donaldson, David A Markland, Helina Loveday, Matthew J Jackson, Hans-Peter Kubis, Appetite (2011).
University, England (UK)