Researchers have found that reducing or increasing daily exposure to sweet-tasting foods over six months does not change how much adults like sweetness or how much they consume.
That finding challenges a central assumption behind dietary advice that targeting sweetness itself can reshape cravings, eating behavior, and health outcomes.
Sweets and daily diets
In the Netherlands, 180 adults cycled through meal plans that made daily eating clearly less sweet, moderate, or much sweeter in the trial.
Using supermarket foods and lab checks, Prof. Katherine Appleton at Bournemouth University and colleagues tracked whether preferences actually moved.
Appleton’s team checked blood and urine markers, breakfast choices, and body weight, and all stayed remarkably similar even when sweet foods changed sharply. Months of menu changes did not rewire what sweetness felt like or what it led to.
Built for real life
Rather than feeding people only test drinks or single snacks, the team shaped about half of what they ate each day.
One group received very little sweetness in provided items, another got a middle level, and a third got much more.
Sugar, fruit, dairy, and sweeteners with few or no calories all supplied sweetness, so the trial tested taste exposure instead of one ingredient.
The real-world design mattered because it tested a practical problem: whether everyday eating can retrain adult preferences outside a lab.
What stayed put
Even at a buffet breakfast, people did not start loading their trays with more sweet foods after sweeter menus.
Researchers also tested lemonade, custard, and cake at several sweetness levels, and the liking pattern barely budged.
Adults still favored familiar items over unfamiliar ones, which suggests recognition mattered more than the study diet itself.
Stable results weaken the idea that repeated sweetness automatically trains the appetite upward over time.
Why sweetness differs
A bowl of fruit and a giant soda can taste sweet for very different biological reasons. Fruit arrives with water and fiber that slow intake, while sugary drinks deliver fast calories.
The World Health Organization (WHO) has long recommended cutting sugar from drinks, juice, syrups, and other sources of added sugar to lower health risks in its guideline.
Inside the body, sugary diets still matter, and the study narrows the problem to what gets absorbed.
Why guidance wobbles
For years, public advice has often treated sweetness itself as a signal that more sugar and calories will follow.
WHO guidance on sweeteners says people should reduce overall dietary sweetness, not only sugar.
The new trial separates those ideas by showing that taste exposure alone did not push people toward heavier eating.
Policymakers now face a clearer task, which is cutting sugar and calories without treating every sweet-tasting food as risky.
Habits snap back
Once the structured menus ended, people drifted back toward the same level of sweetness they had eaten before.
Of the 180 volunteers, 163 finished the intervention and 159 stayed through the later follow-up period.
The rebound suggests people were not simply being stubborn, they were being pulled by well-worn routines.
For policy, the rebound means advice must work with durable habits instead of assuming adult tastes are easy to retrain.
What the scientists say
Public advice that treats sweetness itself as the enemy now looks out of step with this experiment.
“It’s not about eating less sweet food to reduce obesity levels. The health concerns relate to sugar consumption,” Appleton said, arguing that the bigger risk comes from sugar and excess calories.
Appleton’s framing matches the trial’s main result and points prevention toward total sugar, larger portions, and calorie-heavy foods.
Limits of the result
The volunteers were healthy adults, mostly women, and most were not living with obesity or diabetes when they enrolled.
Because children build food habits earlier, the study cannot tell us whether sweetness works differently in early life.
Dutch eating patterns and a relatively health-conscious group may also have limited how far any diet could move.
Study boundaries do not erase the result, but they do narrow how confidently it applies to everyone.
Next steps for diets and sweets
Future studies will need to test children, people with obesity, and groups whose diets are far sweeter than this sample’s.
Researchers may also need to separate foods from drinks, because liquids can deliver sugar much faster to the body.
Another open question is whether early exposure sets long-lasting preferences before adult habits lock in. For now, the strongest conclusion is modest and direct: adult sweet liking looks hard to budge.
Sweetness turned out to be a poor stand-in for the real nutritional problem, which is how much sugar and energy people consume.
Clearer advice could become more precise, and maybe more realistic for people who have tried to quit sweet tastes.
The study is published in The American Journal of Clinical Nutrition.
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