Medical Nutrition Treatment in the Management of Type 2 Diabetes

Goals of Nutrition Therapy for Type 2 Diabetes
Nutritional management aims to help optimize metabolic control and reduce risk factors for chronic complications of diabetes. This includes the achievement of blood glucose and glycosylated hemoglobin (HbA_1c) levels as close to normal as is safely possible, and lipid and lipoprotein profiles, as well as blood pressure values, that may be expected to reduce the risk of macrovascular disease. Individual nutritional needs and the quality of life of the person with diabetes also have to be considered when defining nutritional objectives (7 - 10,14,16,36).

The nutritional recommendation for an individual patient should include practical advice regarding appropriate food choices and quantities. However, it should be stressed that nutritional recommendations for people with type 2 diabetes are similar to those aimed at the population as a whole for the promotion of good health and the prevention of metabolic disorders and vascular complications. Thus, the food for persons with diabetes should not differ appreciably from that recommended for other family members (37 - 39).

Energy Restriction and Body Weight

Many individuals with type 2 diabetes are overweight. Insulin resistance increases with increasing body weight, and obesity may also aggravate hyperlipidemia and hypertension (Fig. 1).

Many short-term studies have demonstrated that weight loss, especially of intraabdominal fat, in persons with type 2 diabetes is associated with decreased insulin resistance, improved glycemic control, reduced blood pressure and improvement of dyslipidemia (Table 1) (35,40).

Thus, energy restriction and weight loss are important therapeutic objectives for obese individuals with type 2 diabetes (7,8,10).

However, long-term data are still scarce to assess the extent to which metabolic improvements by means of weight loss can be maintained in people with type 2 diabetes. Long-term weight loss is often difficult to achieve, and it has to be considered that genetic factors may play an important role in determining body weight.

FIGURE 1 Prevalence of hyperlipidemia and hypertension (n %) by categories of BMI (kg m ^{- 2}) in a sample of 1988 persons with diabetes [930 male, 1058 female; mean age 57 - 13 years; mean diabetes duration 8 years].

Environmental factors also often make losing weight difficult for those genetically predisposed to obesity.