The effects of time-restricted eating vs. standard dietary advice on weight, metabolic health and the consumption of processed food: A pragmatic randomised controlled trial in community-based adults

Weight loss is key to control the increasing prevalence of metabolic syndrome (MS) and its components, i.e. central obesity, hypertension, prediabetes, and dyslipidaemia. We characterised the relationships between eating duration, unprocessed and processed food consumption, and metabolic health. During 4 weeks of observation, 213 adults used a smartphone application to record food and drink consumption, which was annotated for food processing levels following the NOVA classification. Consumption of unprocessed food items showed the highest number of significant associations with MS components after age and sex. In a pragmatic randomised controlled trial, we compared the metabolic benefits of 12h time-restricted eating (TRE) to standard dietary advice (SDA) in 54 adults with an eating duration >14h and at least one MS component. After 6 months, those randomised to TRE lost 1.6% of initial body weight (SD 2.9, p=0.01), compared to the absence of weight loss with SDA (−1.1%, SD 3.5, p=0.19). There was no significant difference in weight loss between TRE and SDA (between-group difference −0.88%, 95% confidence interval −3.1 to 1.3, p=0.43). Our results show the potential of smartphone records to predict metabolic health and highlight that further research is needed to understand individual responses to TRE.