A randomized controlled trial in 180 adults found that prescribing diets high, regular or low in sweet-tasting foods for six months did not change participants’ liking for sweet taste, body weight, energy intake, or several biomarkers linked to diabetes and cardiovascular disease. The researchers concluded the results do not support public health advice that aims to reduce exposure to sweet-tasting foods regardless of whether sweetness comes from sugar, low-calorie sweeteners, fruit or dairy.
Researchers at Wageningen University & Research in the Netherlands and Bournemouth University in the UK report that altering “whole-diet” exposure to sweet taste over six months did not change adults’ preference for sweetness or improve several commonly used health indicators.
The study—known as the Sweet Tooth Trial and published in the American Journal of Clinical Nutrition—randomly assigned 180 healthy adults to one of three groups designed to differ in how much of their provided foods and beverages tasted sweet: a low sweet-taste exposure group (61 participants), a regular exposure group (60), and a high exposure group (59). Sweet taste was supplied through a mix that included sugars, low-calorie sweeteners, and naturally sweet foods such as fruit and dairy, according to the paper.
Across the intervention, the researchers assessed outcomes including sweet taste liking, perceived sweet taste intensity, food choice and energy intake, body weight, and biomarkers related to diabetes and cardiovascular disease. The trial’s main comparison was change from baseline to month 6, and the team also reports follow-up measurements after the intervention.
The researchers found no significant differences between groups in changes in sweet taste liking or perceived intensity, and they also report no group differences in energy intake, body weight, or the measured diabetes and cardiovascular disease markers over the six-month period. While dietary and urinary measures indicated that sweet-taste exposure differed between groups during the intervention, the paper reports that participants returned to baseline levels of sweet food intake after the intervention.
Katherine M. Appleton, a professor of psychology at Bournemouth University and the study’s corresponding author, said the findings do not support guidance that seeks to reduce sweet taste exposure in general—independent of other factors—because the trial did not find that eating less sweet-tasting food reduced preference for sweetness.
The authors argue that, based on their results, public health messaging that broadly targets “sweetness” may need reconsideration, and that other characteristics of foods—such as energy density and food form—remain important when addressing diet-related health risks.
The trial was registered at ClinicalTrials.gov as NCT04497974.
