High free sugar intakes are associated with a number of global health concerns, including dental caries (such as tooth decay and cavities), overweight, and cardiovascular disease.
This has resulted in current recommendations from the World Health Organisation (WHO) for a reduction in free sugar intakes for all adults and children to less than 10% of total energy intake, with added health benefits for reductions to 5%.
Within these recommendations, the WHO calls for research into strategies for reducing free sugar intakes, and suggests that reducing exposure to sweet taste (regardless of the source of the sweet taste) may be useful.
Reducing free sugar intakes will improve individual health and well-being, particularly over the long-term, but we recognise that a lot of people like sweet foods, so it may not be easy to reduce this intake.
Our work addresses this concern in the general population, with the aim of encouraging healthy diets and improving population-wide health.
Aiming to reduce free sugar intakes
We have conducted studies investigating attitudes towards sugars, sweeteners and sweet taste (Tang et al., 2021; Tang et al., 2024), and have published systematic reviews investigating the effects of low-calorie sweeteners (Rogers & Appleton, 2021; Greyling et al., 2020) and sweet taste exposure (Higgins et al., 2022) on body weight, energy intake and related biological mechanisms.
We are also currently conducting a large randomized controlled trial, where three different types of dietary recommendations for reducing free sugars, providing nutrient, food and food-substitution-based information, will be tested against a control (Boxall et al., 2024). Effects of the recommendations on free sugar intakes, diet composition, and anthropometry will be assessed over a 12 week period. Results of this study will be published in 2025.
Reducing exposure to sweet taste
Various projects of ours now suggest limited benefit from reducing our exposure to sweet taste for impacts on sweet taste preferences and subsequent intakes.
In a systematic review published in 2018, we found few effects of sweet taste exposure on preferences for other sweet foods in existing studies (Appleton et al., 2018).
Since this publication, we have run two medium-term intervention studies, where participants were exposed to either a sweet breakfast or a non-sweet breakfast for three weeks (Appleton et al., 2022), or were asked to increase, decrease or maintain their dietary sweet food intake for one week (Bielat et al., 2025). In both studies we found no effects of increased or decreased sweet taste exposure on subsequent sweet food preferences or intakes.
In partnership with Wageningen University and Research, we are now running a large long-term study, where 180 participants will be asked to increase, decrease or maintain their dietary sweet food intake for 6 months (Cad et al., 2023). Effects will be investigated in sweet food preferences, sweet food choice, energy intake and body weight and various biochemical markers for health. Results from this work will be published in 2025.