Dietary Goals and Exercise
The treatment goals for a diabetes diet are the following:
- To achieve near-normal blood glucose levels. People with type 1 diabetes must coordinate calorie intake with medication or insulin administration, exercise, and other variables to control blood glucose levels. New forms of insulin are now allowing more flexibility in timing meals.
- To protect the heart and aim for healthy lipid (cholesterol and triglyceride) levels and control of blood pressure.
- To achieve reasonable weight. Overweight type 2 diabetics who are not taking medication should aim for a diet that controls both weight and glucose. A reasonable weight is usually defined as what is achievable and sustainable, rather than one that is culturally defined as desirable or ideal. Children, pregnant women, and people recovering from illness should be sure to maintain adequate calories for health.
- To manage or prevent complications of diabetes. People with diabetes, whether type 1 or 2, are at risk for a number of medical complications, including heart and kidney disease. Dietary requirements for diabetes must take these disorders into consideration.
- To promote overall health.
Overall Guidelines. There is no longer a single diabetes diet that will suit everyone. The overall approach is based on the U.S. Dietary Guidelines for healthy eating for all Americans, and includes the following:
- Overall, experts recommend that foods containing carbohydrate from whole grains, nuts, fruits, vegetables, and low-fat milk should be included in any healthy diet.
- Carbohydrates and monounsaturated fat should provide 60% to 70% of calories, but the mix should depend on calorie intake needed for weight loss or maintenance.
- Avoid saturated fats (found in animal products) and trans fatty acids (hard margarines, commercial products, fast foods). In selecting fats or oils, prefer monounsaturated fats (virgin olive oil, canola oil), although also include polyunsaturated oils as well (sunflower, rapeseed). Of note, a 2001 report suggested that trans fatty acids were a risk factor for type 2 diabetes while polyunsaturated were protective.
- Limit protein. Protein should provide 15% to 20% total calories (less in people with nephropathy.) In selecting proteins, eat in moderation and prefer fish or soy protein to poultry or meat. (Avoid, in any case, high-fat meats.)
- When choosing foods with sugar, choose fresh fruits, but do so in moderation.
[For detailed information, seeWell-Connected Report #42 Diabetes Diet.]
Healthy Weight Control
Weight gain is a potential side effect of intense diabetic control with insulin. Being overweight can increase the risk for health problems. On the other hand, studies suggest that more than one-third of diabetic women omit or underuse insulin in order to lose weight. Eating disorders have become a serious problem within the general population and are especially dangerous in diabetics. Some evidence suggests that they contribute to about 20% of cases of recurrent ketoacidosis in young women. Ketoacidosis is significant complication of insulin depletion and can be life threatening.
Aerobic exercise is proving to have significant and particular benefits for people with type 1 diabetes. It increases sensitivity to insulin, lowers blood pressure, improves cholesterol levels, and decreases body fat. Because glucose levels swing dramatically during workouts, people with diabetes need to take certain precautions:
- They should monitor glucose levels carefully before, during, and after workouts.
- Patients should probably avoid exercise if glucose levels are above 300 mg/dL or under 100 mg/dL.
- To avoid hypoglycemia, diabetics should inject insulin in sites away from the muscles they use the most during exercise.
- Before exercising, they should also avoid alcohol and if possible certain drugs, including beta-blockers, which increase the risk of hypoglycemia.
- Insulin-dependent athletes may need to decrease insulin doses or take in more carbohydrates, especially in the form of pre-exercise snacks. Skim milk is particularly helpful. They should also drink plenty of fluids.
- Good, protective footwear is essential to help avoid injuries and wounds in the feet.
Resistance or high impact exercises should be avoided. They can strain weakened blood vessels in the eyes of patients with retinopathy. High-impact exercise may also injure blood vessels in the feet. Because diabetics may have silent heart disease, they should always check with their physicians before undertaking vigorous exercise.