(Photo by Katya Wolf via Pexels)
By Stephen Beech
A "sweet tooth" is down to genes rather than diet, suggests new research.
Eating more or less sweet-tasting food doesn’t change how much people like sweet flavors, say scientists.
The findings of a series of controlled trials suggest that eating more sweet-tasting food doesn’t increase someone’s preference for sweet tastes.
After six months on diets with varying amounts of sweet foods, the study participants' preference for sweetness stayed the same, no matter how much sweet-tasting food they ate.
Lead investigator Professor Kees de Graaf said: “We also found that diets with lower or higher dietary sweetness were not associated with changes in energy consumption or body weight.
“Even though many people believe that sweet foods promote higher energy intake, our study showed that sweetness alone isn’t to blame for taking in too many calories."
Prof de Graaf, of Wageningen University in the Netherlands, added: “Most studies examining the effects of repeated exposure to sweet taste on the liking, or preference, for sweetness have been short-term, covering periods up to one day.
(Photo by nappy via Pexels)
“Without consistent data on the longer-term effects, the basic question of whether or not sweetness preferences are modifiable has been unanswered.”
The new research was based on a validated approach to measuring sweet taste preferences using foods and drinks developed especially for the trial and not administered as part of the intervention diets.
Three groups of 60 volunteers, 180 participants in total, were each given diets with mostly sweet, less sweet or a mix of foods.
That was done by delivering food and drink packages every two weeks for six months, providing about half of each participant’s daily food items.
The participants received daily menus for guidance, but could eat as much or as little of the provided foods as they wanted.
The research team categorized foods based on their sweetness using data from a previous study that measured taste intensity in about 500 commonly eaten Dutch foods.
Sweet products included jam, milk chocolate, sweetened dairy and sugar-sweetened drinks.
(Photo by Lina Kivaka via Pexels)
Non-sweet items included ham, cheese, peanut butter, hummus, salted popcorn and sparkling water.
Each person’s preference for sweet taste was tested before the intervention diet began, twice during the diet, directly after the diet ended, and one and four months after people were no longer following the assigned diet.
The research team also looked at total energy and macronutrient intake, dietary intakes during the trial and physiological measures such as body weight, body composition and blood markers for the risk of diabetes and cardiovascular diseases.
The researchers found that lower exposure to sweet-tasting foods did not lead to shifts in sweet taste preferences, changes in sweet taste perception, changes in food choice or energy intake.
And the group eating more sweet-tasting foods did not experience an increased preference for sweet foods.
The research team also found no association between the amount of sweet foods consumed and changes in body weight or biomarkers for diabetes and cardiovascular disease.
Prof de Graaf said: “This is one of the first studies to measure and adjust sweetness across the whole diet within a realistic range of what people actually consume.
“This matters because some people avoid sweet-tasting foods, believing that regular exposure will increase their preference for sweetness - but our results show that’s not the case.”
The findings were presented at the annual meeting of the American Society for Nutrition in Orlando, Florida.
