The epidemic of overweight and obesity is a major driver of the growing prevalence of type 2 diabetes mellitus globally. The risk of type 2 diabetes increases exponentially as body mass index rises above 25 kg/m(2). Obesity currently costs the Canadian economy approximately $7.1 billion annually whereas per capita health care cost for individuals with diabetes are 3 to 4 times that for persons without the disease. Each kilogram of weight lost through health behaviour changes in people with impaired glucose tolerance is associated with a relative diabetes risk reduction of 16%. As 80% to 90% of people with type 2 diabetes are overweight or obese, and adiposity worsens the metabolic and physiologic abnormalities associated with type 2 diabetes, weight loss is recommended as the cornerstone management measure. A modest weight loss of 5% to 10% is an achievable and realistic goal for preventing type 2 diabetes in susceptible individuals and improving glycemic and metabolic control in people with type 2 diabetes. When health behaviour modification fails to achieve glycemic and metabolic goal targets, priority should be given to antihyperglycemic agents that are associated with weight loss or weight neutrality. Every pound of body fat loss matters and every kilogram counts in the management of type 2 diabetes.