Imbalance between energy gained and consumed contributes to weight gain and fat accumulation in body. Body Mass Index when equalled and increased above 25 kg/m 2 is classified as overweight and equalled and above 30 kg/m 2 as obesity. Overweight and obesity is a global problem carrying immense health and economic consequences on individuals’ lives. In the context of Pakistan, which is facing double burden of nutrition, carrying out a study on excess weight is of utmost importance. The objective of the present study is to ascertain the possible causes and consequences of overweight and obesity among adult population using Pakistan Panel Household Survey for year 2010. The results of the present research show 30 percent of the excess weight adults in Pakistan. Furthermore, along with certain background demographic and social characteristics, study chooses physical activity to be the significant determinant of excess weight. The findings also show a negative association between weight and health by yielding higher prevalence and intensity of disease among excess weight than non-excess weight adults. Cost of illness methodology is adopted in the study on the prevalence and cost of two major obesity co-morbidities i.e. heart disease and diabetes. It indicates that a sizeable proportion i.e. 22 percent of illness and its cost incurred by the individuals for these co-morbidities is attributed to overweight and obesity. According to the results, share of medical cost for heart diseases and diabetes is 16 percent of the national total health expenditure in Pakistan due to excess weight which creates a huge cost burden on oversized individuals. Therefore, it is a high time to include strategies in the country health plans concerning control and prevention of overweight and obesity. This will provide a roadmap to a sustainable health care system and increased economic wellbeing of individuals. Supervisor:- Dr Durre Nayab