Having a sweet tooth not always linked to being overweight

Sugar is the latest target in the fight against obesity, with calls for Australia to follow the lead of countries such as the UK, Mexico and Hungary and introduce a tax on sugary drinks. But does having a sweet tooth mean you are more prone to being overweight or obese?

In their latest study, scientists with Deakin University's Centre for Advanced Sensory Science (CASS) have found that there is not a strong connection between sweet taste, diet and body size.

The results from this comprehensive lab-based study suggest that sweetness is not necessarily what drives people to eat the types of food that can lead to weight problems, said the head of CASS, Professor Russell Keast.

"The relationship between sweet taste, food intake and overweight/obesity has been controversial as studies in this area have not come up with consistent findings. That we found that sweet taste, measured using many different methods, was not associated with BMI or waist measurements is really not that surprising," Professor Keast said.

"Consumers have the choice of foods which taste sweet but don't have the energy from sugar through the use of low calorie sweeteners. Soft drinks are a good example, one may contain lots of energy, the other none but they are both equally sweet. Consumers can get their sweet buzz without the energy."

Professor Keast said that considering their study results in light of a potential sugar tax is "intriguing".

"One school of thought would be that since there is no association between how we perceive sugars and BMI or waist measurements, singling out sugar is not warranted, so the focus should be more on the whole diet," he said.

"An alternate view is any initiative that reduces consumption of nutrient void sugar rich foods, for example sugar sweetened beverages, has the potential to benefit public health. And certainly any initiative that helps reduce children's consumption of drinks high in sugar is also positive."

During this study participants attended 16 separate lab sessions in which they tasted samples of a range of commercially available sweeteners (from natural sugars to artificial sweeteners). Multiple measures of sweet taste were assessed at a range of intensities. Height, weight and waist were measured and participants also completed questionnaires on their food intake. The 60 participants were aged between 18 and 52 years, 28 were male, 32 female, with 38 in the normal weight range while 22 were overweight/obese.

PhD student Julia Low who ran the study said one interesting result was that perceived sweetness was found to be weakly to moderately associated with total energy intake.

"So the more sweetness you experience from a range of sweeteners the more likely you were to have a higher energy diet," Ms Low said.

"The continued increase in the worldwide rate of nutrition-related chronic illness such as obesity demands an increased understanding of the drivers of food intake," Professor Keast said.

"Taste is undoubtedly one driver of food intake but the lack of association between sweet taste and BMI reinforces the complexity in developing effective strategies to reduce obesity. We certainly need a better understanding of high intensity sweeteners in the food supply and the role they may play weight maintenance."

The study titled 'The association between sweet taste function, anthropometry, and dietary intake in adults' is published online in the international journal Nutrients.