Effective management of diabetes mellitus requires lifelong adherence to a plan that incorporates lifestyle changes, exercise and diet. Following a dietary plan is a fundamental component of diabetes management because this can regulate the body's supply of glucose and lipids, resulting in weight reduction, an improved response to pharmacotherapies, and optimal control of the patient's glycaemic status and lipid profile. This article examines the components of nutrition therapy recommended for people with diabetes. Initially, the patient's daily calorie requirements should be determined, and therapeutic objectives should be decided that take into account the individual's clinical profile and personal preferences. Subsequently, a dietary plan should be negotiated with the patient that considers the carbohydrate, protein, fat and fibre content of each food item.