A narrative review of the current literature into the impacts of fasting on levels of impulsivity and psychological stress

The impacts of dietary fasting on humans remains relatively under researched despite a biological basis for its function in human life. This narrative mini-review aims to summarise the current, limited, research and make future recommendations. Studies were identified using the databases, Psych Info and Web of Science, and search engine Google Scholar; those concerned with eating disorders or disordered eating were excluded. The paper demonstrates how there is largely now more evidence to suggest that dietary fasting would have beneficial outcomes in humans, whilst highlighting various methodological flaws in this area of research. We summarise the assumptions that have been made from animal models and insufficiently replicated with human subjects and identify where further contradictory findings have been reported in areas such as psychological wellbeing due to the heterogeneity of the methodologies used. We conclude that more stringent controls and mixed methodology longitudinal studies are required, looking at both neurophysiological and psychosocial factors simultaneously over time.