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

Phillips, N. E.; Mareschal, J.; Schwab, N.; Manoogian, E. N. C.; Borloz, S.; Ostinelli, G.; Gauthier-Jaques, A.; Umwali, S.; Gonzalez Rodriguez, E.; Aeberli, D.; Hans, D.; Panda, S.; Rodondi, N.; Naef, F.; Collet, T.-H.

The prevalence of metabolic syndrome (MS) is increasing, affecting approximately 1 billion people. Weight loss is key to control MS components, i.e. central obesity, hypertension, prediabetes, and dyslipidemia. Here, we characterised the relationships between eating duration, unprocessed and processed food consumption, and metabolic health. In a 4-week observation phase, 213 Swiss adults recorded consumed meals and drinks with a smartphone application, and these were annotated for food processing levels according to the NOVA classification. Regression analysis showed that the number of unprocessed food items showed the highest number of significant relationships with MS components after age and sex. Next, in a randomised controlled trial, we tested whether 12-hour time-restricted eating (TRE) for 6 months leads to metabolic benefits compared to standard dietary advice (SDA), in adults who ate >14h per 24h cycle and had at least one MS component. Twenty-eight adults were randomised to TRE and lost 1.6% of initial body weight (SD 3.0%, p = 0.02), compared to the 26 in the SDA arm whose weight was stable (-1.1%, SD 3.4%, p = 0.17). No significant difference in body weight reduction was observed between TRE and SDA (p = 0.56). Overall, our results show the promise of smartphone records to predict metabolic health, and highlight that further research is needed to understand individual responses to TRE and SDA.