My research explores the biopsychosocial factors associated with overeating and obesity. The prevalence of obesity has increased globally over the past four decades, and one of the primary factors implicated is the increased availability of highly processed, inexpensive, energy-dense foods that offer palatability but little nutritional value. However, not all humans are obese, suggesting that individual and environmental factors play a role in moderating eating behaviour and responses to palatable food cues. My research investigates (a) how the increased availability of highly palatable energy-dense foods, served in large portions yet containing little nutritional value, impacts appetite and amounts eaten; (b) how the individual variation in psychological, physiological, biological and socio-economic characteristics increases the susceptibility to overeating these foods.