Dominic O’Connor, a SWEET consortium member in Work Package 2 from the University of Leeds, has completed his PhD project. Dominic’s thesis, ‘Sweet Food Preferences and Associated Appetite Regulatory Mechanisms’ has two primary contributing studies examining sweet food preferences in the context of obesity.

The first study provides an examination of the stability of sweet food preferences among women with overweight and obesity during a period of dietary induced weight loss. The findings here show that throughout a single day, sweet food preferences demonstrate variability, changing depending on time of day measured due to the nutritional status of an individual. However, over a period of weight loss, preferences remained highly stable.

The implications of these findings show significance for future research in assessing food preferences, with time of day exerting influence over sweet food preferences in particular. As such, when food preferences are a primary outcome of a study, the time of day in which they are assessed should be carefully considered. The study also highlights that two different dietary weight loss protocols did not differ in their effects on sweet food preferences, leading to the conclusion that the method of weight loss may be of less important than the weight loss itself, when food preferences are altered. Based on these findings the author concluded that one can confidently identify individuals on the basis of their sweet food preferences.

Dominic has played a pivotal role within the data collection of the SWEET work package 2, phase 2 trial, and used this data as the second study in his project. Dominic’s findings here demonstrated that consumption of a sweet biscuit produced an immediate decrease in liking and wanting for sweet foods. There was also a reduction in sweet preferences following repeated consumption of the intervention products. However, these effects did not differ across the sweetener conditions, leading to the conclusion that sweetener type is of less concern than previously thought. It is the consumption of a sweet stimulus in and of itself that is likely to impact subsequent preferences. These findings may partly serve to dispel concerns that consumption of sweeteners serves to increase subsequent sweet cravings and intake, a concern often expressed amongst the media and consumers. These findings have been reiterated within a narrative review which Dominic co-authored with SWEET colleagues, published in the journal Food & Function.
In October 2022, Dominic presented both sets of findings at the International Congress on Obesity, in Melbourne, Australia.

As Dominic finishes his studies we wish him the best of luck with his thesis defence and future work.