For six months, a group of volunteers ate diets built around either a lot of sweet tasting food or very little of it. By the end of the trial, their appetite for sugar had barely moved.
That is the central finding of a new study led by researchers in the Netherlands and England, published in the American Journal of Clinical Nutrition. The results push back against a piece of dietary advice repeated for years by public health agencies, the idea that trimming sweetness from meals will gradually shrink a person’s craving for it.
A trial built to test an old assumption
Scientists at Wageningen University in the Netherlands and Bournemouth University in England recruited 180 adults for the project. Participants were split into three groups. One followed a diet loaded with sugary tasting foods, a second stuck to a low sweetness diet, and a third ate at an average level. The sweetness in each diet came from a mix of sources, including added sugar, naturally sugary foods like fruit, and low calorie sweeteners.
Researchers checked in with participants after one month, three months and six months, asking how their liking for sugary foods and their perception of sweetness had changed. Blood and urine samples were also collected to track markers tied to diabetes and cardiovascular risk, alongside regular measurements of body weight.
What six months of data showed
None of it moved much. Body weight stayed roughly flat across all three groups, and the diabetes and heart disease markers researchers tracked showed no meaningful differences either. People eating more sugary food did not develop a stronger craving for sugar, and people eating less of it did not lose their taste for sweetness. Many participants also drifted back toward their original eating habits once the structured part of the trial ended, suggesting the shift in diet had little lasting pull on behavior.
Sweetness and sugar are not the same thing
The research team argues the results point to a flaw in how sweetness gets treated in nutrition guidance. Organizations including the World Health Organization have encouraged people to cut back on sugary tasting foods broadly, without distinguishing where that sweetness comes from. A piece of fruit and a sugary snack can taste equally sugary while offering very different nutritional value, since fruit also carries fiber and vitamins that processed foods typically lack.
Katherine Appleton, a professor of psychology at Bournemouth University and the study’s corresponding author, has pointed to sugar and energy density as the more useful targets for public health messaging, rather than sweetness itself. Some fast food items barely register as sugary yet carry heavy sugar loads, while naturally sweet foods like fruit and dairy can still support a healthy diet.
What this means for public health advice
Energy dense foods, meaning foods packed with calories relative to their size, tend to be the common thread in weight gain and related health risks, according to the research team. Many ultra processed products fall into that category because of how much added sugar and fat they contain, regardless of how sugary they taste on the tongue.
The findings suggest that steering people away from sugary flavors alone will not necessarily improve health outcomes or curb cravings over time. Instead, the researchers say future guidance may do more good by focusing on sugar content and overall calorie density, giving people a clearer target than sweetness ever provided.
