Why Diets Fail

About the lecture

In this lecture, we think about some of the successes and failures in dieting, focusing in particular on: (i) the fact that around 80-90% of people who lose weight will regain some of it in a year, with a proportion gaining more weight than they lost originally; (ii) three key mechanisms for why diets fail being their strict and unsustainable rules, the need to keep reducing calorific intake to continue losing weight, and the body’s changing responses to the ghrelin and leptin hormones; (iii) the ironic process as a psychological explanation for the failure of dieting, which posits that dieting puts eating at the forefront of the mind, making it a bigger part of everyday thoughts than when not dieting; (iv) Daniel Wegner’s ‘white bear experiment’ as an example of this psychological effect; (v) the series of connected events which make up the sparrow model; (vi) the restraint eating theory, which states that ignoring internal cues for hunger/satiation uses up cognitive resources; (vii) disinhibition theory, which states that minor deviations from the diet can lead to binging; (viii) the boundary model, which states that individuals undertaking dieting have smaller boundaries of hunger and fullness, which can lead to increased eating; (ix) some suggestions for how to overcome failed diets including by focusing on maintaining, rather than losing, weight and eating a balanced diet, rather than thinking of food as good or bad; (x) orthorexia nervosa, a condition which manifests as an obsession with healthy eating.

About the lecturer

Dr Laura Renshaw Vuillier is a senior lecturer in the Department of Psychology at Bournemouth University. Dr Renshaw-Vuillier’s research interests surround the neural basis of emotion processing and regulation in eating disorders, as well as developing early interventions to help young people with gambling problems. Some of Dr Renshaw-Vuillier’s recent publications include 'The impact of the COVID-19 pandemic on individuals with eating disorders: the role of emotion regulation and exploration of online treatment experiences' (2021) and 'Believing emotions are uncontrollable is linked to eating disorder psychopathology via suppression and reappraisal' (2021).