“…Indeed, data from randomized controlled trials of structured group weight-loss interventions indicate that, on average, 80% of patients who enrol in such programmes go on to complete the treatment (Wadden & Butryn, 2003), with completers achieving a mean weight loss of 8e10% of their initial body weight within roughly 30 weeks (Wadden & Butryn, 2003). According to the 2013 Guidelines for the Management of Overweight and Obesity in Adults (Jensen et al, 2014), this amount of weight loss can be considered successful (i.e., in line with a 5e10% reduction of initial weight), being associated with a significant reduction in the incidence of type-2 diabetes (Knowler et al, 2002), and clinical improvements in weightrelated medical comorbidities (e.g., sleep apnoea, diabetes, hypertension, hyperlipidaemia) (Jensen et al, 2014), and psychosocial outcomes (e.g., mood, quality of life, and body image) (Dalle Grave et al, 2007;Faulconbridge et al, 2012;Fontaine, Barofsky, Bartlett, Franckowiak, & Andersen, 2004).…”