Monitoring During Different Intermittent Fasting Protocols in Non-Obese Adults

The prevalence of overweight has risen considerably all over the world in the past century. Epidemiological studies have shown that, starting from a body mass index of 20-21 kg/m2, increasing BMI levels are associated with progressively increased risks of developing diabetes, cardiovascular disease, several types of cancer and other diseases. The problem is pronounced by the unlimited and constant availability of food. Treatment of overweight is still difficult and finding effective and more personalized strategies to manage these conditions is crucial. Intermittent fasting has been suggested as an alternative way to address these problems. Intermittent fasting is an eating pattern that involves rotating periods of eating and fasting. Animal studies and previous human clinical trials have provided evidence that various types of intermittent fasting lead to weight loss and improved health markers not only in obese, but also in healthy, non-obese adults.There are several types of intermittent fasting. The most popular version is time-restricted feeding (TRF), which allows ad libitum (at one's pleasure) energy intake within a defined period of time each day (6-12h). Another subtype of IF is called alternate day fasting (ADF). ADF is defined as 'feast days' on which food is consumed ad libitum, which alternate with 'fast days' on which food is withheld or reduced. However, despite the growing popularity of intermittent fasting, it is not clear which type of IF is most effective and what fasting window is needed to induce beneficial effects. Additionally, tools to longitudinally track personal progress of dieting are lacking. Therefore, the main objective of this study is to compare the effects of each of two different intermittent fasting protocols (TRF and ADF) on metabolic parameters to a control group. Furthermore, a new dynamic measurement technique, using breath analysis, will allow to better monitor the progress of individual participants.