Obesity has reached epidemic proportions becoming a major global public health challenge since it is associated with an increased risk of type 2 diabetes, cardiovascular disease, stroke, arthritis and some forms of cancer. Therefore, a large number of strategies have been investigated in order to induce a negative energy balance and consequently body weight loss mainly inducing a low calorie diet and sometimes accompanied by an increase in physical activity. However, individual responses to body weight loss interventions vary widely and several studies have aimed to identify psychological, behavioral and personal predictors of this variability.