Effects of a six-day, whole-diet sweet taste intervention on pleasantness, desire for and intakes of sweet foods: a randomised controlled trial

Reduced exposure to sweet taste has been proposed to reduce sweet food preferences and intakes, but the evidence to support these associations is limited. This randomised controlled trial investigated the effects of a whole-diet sweet taste intervention for 6 d, on subsequent pleasantness, desire for and sweet food intakes. Participants (<i>n</i> 104) were randomised to increase (<i>n</i> 40), decrease (<i>n</i> 43) or make no change to (<i>n</i> 21) their consumption of sweet-tasting foods and beverages for 6 consecutive days. Pleasantness, desire to eat, sweet taste intensity and sweet food and beverage intakes were assessed on days 0 and 7. One hundred and two (98 %) participants completed the study, and self-reported adherence with the dietary interventions was moderate to good (M = 66-72/100 mm), with instructions to decrease sweet food consumption reported as more difficult than the other diets (smallest (<i>t</i>(81) = 2·45, <i>P</i> = 0·02, <i>M</i> _<i>diff</i> = 14/100 mm, se = 2 mm). In intention-to-treat analyses, participants in the decreased sweet food consumption group reported higher sweet taste intensity perceptions at day 7 compared with day 0 (<i>F</i>(2101) = 4·10, <i>P</i> = 0·02, <i>M</i> _<i>diff</i> = 6/100 mm, se = 2 mm). No effects were found for pleasantness (<i>F</i>(2101) = 2·04, <i>P</i> = 0·14), desire to eat (<i>F</i>(2101) = 1·49, <i>P</i> = 0·23) or any of the measures of sweet food intake (largest <i>F</i>(2101) = 2·53, <i>P</i> = 0·09). These results were confirmed in regression analyses that took self-reported adherence to the diets into account. Our findings suggest that exposure to sweet taste does not affect pleasantness, desire for or intakes of sweet-tasting foods and beverages. Public health recommendations to limit the consumption of sweet-tasting foods and beverages to reduce sweet food preferences may require revision.