June 2025 - Sensory Science and Eating Behaviour Chair Group Presents new findings of two large RCTs at the American Society for Nutrition (ASN) ‘NUTRITION 2025’ meeting in Orlando

SSEB Chair Prof. Forde, alongside Assistant Prof. dr Marlou Lasschuijt shared
the first findings from the RESTRUCTURE project which sought to test whether
meal texture moderates eating rate and energy intake from ultra-processed diets
(www.restructureproject.org).
Later in the week, Emeritus Prof Kees de Graaf and Eva Cad revealed the
outcomes of a sweet taste intensity on sweetness preferences in the i-Sense
project (https://www.wur.nl/en/project/sweet-tooth-nature-or-nurture.htm).

Prof. Ciarán Forde and Assistant Prof. Marlou Lasschuijt presentedthe result of the RESTRUCTUREproject which ran from 2021-2025. The main RCT was a comparison of daily energy intakes over a 14-day diet intervention comprising melas with textures that promote a faster eating speed, or a slower eating speed, with a 14-day wash out between each diet arm. The trial was conducted at the Human Nutrition Research Unit at WageningenDivision of Human Nutrition and Health, and included serving 3,444 meals (!!) to 41 participants who completed a 7 week semi-residential diet intervention trial to compare daily energy intakes on each diet arm. Results showed that meal texturehad a consistent effect on meal eating ratewith >90% of participants responding to the meal texture intervention. This effect was sustained over the 14 days of each diet and had a consistent effect on how much energy people consumed, with participantsconsuming on average 369 fewer kcals per day on the slower-eating UPF diet compared to the faster UPF version. All meals were equally liked, matched for nutrient composition and energy density, and eaten to an equivalent amount of fullness and satisfaction.The cumulative effect of the differences in eating rate was over 5,200 kcal less energy consumed over the 14-days of the slower UPF diet compared to the faster UPF diet. Findings from this landmark study have important implications in terms of our understanding of mechanisms to explain previously observed differences in energy intake from diets high in UPF and highlight the importance of sensory cues, such as meal texture, in shaping consumer eating behaviours and the potential for such cues to produce sustained changes in consumer eating behaviour and intake.

Later at the same conference, Prof. Kees de Graaf and PhD candidate Eva Čadpresented the outcomes of the i-Sense ‘sweet tooth’ (nature or nurture) trial. The study has been underway since 2020 and tested whether sweet taste preferences can be adjusted in response to diets that are either low, medium or higher in sweet taste intensity. The trial was a between groups comparison of three groups of participants (n=60 in each arm), where each group completed a six-month dietary taste intervention of low, medium or high amounts of sweet tasting foods in their diet, where the primary outcome was changes in sweet taste preferences. The study that that despite significantdifferences in sweet exposure between the diets this did not result in changes to sweet taste preferences, and these preferences remained the same as when compared to baseline. These findings are important in terms of our understanding of how malleable sweetness preferences are, and highlight that even after an extended period of high or low sweetness exposure, participants preferences are unlikely to change significantly. The study was led at WUR by Associate Prof. Monica Mars with collaboration from Prof. Katherine Appleton at University of Bournemouth UK, and was a huge team effort to ensure the successful delivery of the taste manipulation. The findings of i-sense have implications for public health strategies aimed at reducing sugar intake and shifting consumer preferences in the future. Eva will defend her PhD thesis on Friday the 13^thof June and we congratulate her on her hard work on the i-Sense trial.

Together, these presentations sparked widespread interest and discussion among attendees about the role of sensory experience in shaping our long-term eating behavioursand dietary patterns and offer new direction for sensory based approaches to shift consumers to healthier diets that maintain eating enjoyment and satisfaction. The SSEB team will present further findings from both RESTRUCTURE and i-Sense at the forthcoming IUNS-ICN congress in Paris (August 22^nd- 26^th2025).