The two major forms of diabetes are type 1, also known as insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes, and type 2, also called non-insulin-dependent diabetes mellitus (NIDDM) or maturity-onset diabetes. Both types share one feature: Elevated blood sugar (glucose) levels due to absolute or relative insufficiencies of insulin, a hormone produced by the pancreas. Insulin is a key regulator of the body’s metabolism.

In type 1 diabetes, the pancreas does not produce insulin. Onset is usually in childhood or adolescence. Type 1 diabetes is considered an autoimmune disorder. Individuals with type 1 diabetes need to take insulin. Dietary control is very important. Treatment focuses on balancing insulin intake with food intake and energy expenditure from physical exertion.

Type 2 is the most common form of diabetes, accounting for 90 to 95 percent of cases. In type 2, the body does not respond normally to insulin, a condition known as insulin resistance. Patients with type 2 diabetes are either diet-controlled or may have to take medications and/or insulin injections.

Patients whose blood glucose levels are higher than normal, but are not yet high enough to be classified as diabetes, are considered to have pre-diabetes. It is very important that people with pre-diabetes control their weight to stop or delay the progression to diabetes.

Obesity is common in individuals with type 2 diabetes, and this condition appears to be related to insulin resistance. The primary dietary goals for overweight patients with type 2 diabetes are weight loss and weight maintenance. With regular exercise and diet modification programs, many people with type 2 can minimize or even avoid medications. Weight loss medications or bariatric surgery may be appropriate for some people.

For people who have diabetes, the treatment goals for a diabetes diet include:

1. Achieving near-normal blood glucose levels to prevent eye, kidney and nerve complications from diabetes.

2. Aiming for healthy lipid (cholesterol and triglyceride) levels and controlling blood pressure to protect the heart.

3. Achieving reasonable weight, which is usually defined as what is achievable and sustainable and helps achieve normal blood glucose levels.

Even modest weight loss can improve insulin resistance, which is the main problem in patients with pre-diabetes or diabetes and are overweight or obese. Physical activity, even without weight loss, is very important.

Individuals with pre-diabetes or diabetes should consult their primary-care physician or a registered dietitian who is knowledgeable about diabetes nutrition. There is no such thing as a single diabetes diet.

Dr. Wajahat Kahn wrote this article. He specializes in family medicine at the Franciscan Medical Clinic in Gig Harbor. The clinic is part of Franciscan Health System, which includes St. Joseph Medical Center in Tacoma, St. Francis Hospital in Federal Way, St. Anthony Hospital in Gig Harbor, St. Clare Hospital in Lakewood and St. Elizabeth Hospital in Enumclaw.