Hamburger or veggie burger? Carbohydrates are not the only factor in the diabetic diet

This study examined whether a processed meat-based meal led to abnormal increases in insulin (the hormone that breaks down glucose), glucose or hormones in patients with type 2 diabetes.

The main treatment goal of type 2 diabetes is the control of blood glucose (sugar) levels. Carbohydrates are the nutrients that are turned into glucose in the body. As a result, it is recommended that patients with type 2 diabetes limit foods that are high in carbohydrates (such as rice, pasta and bread). However, other nutrients can also have an effect on blood glucose levels. For instance, saturated fat (found in meat or cheese) is known to decrease insulin sensitivity (how effectively the body uses insulin). Meals high in saturated fat or protein can also increase glucose levels in the body after eating. 

A diet high in meat, particularly red and processed meats (salted fish, hot dogs), has previously been associated with a 38% increase in the risk of diabetes. On the other hand, a vegetarian diet has been shown to improve insulin sensitivity and blood glucose levels compared to the typical diet recommended for diabetics. It is not clear what differences can be seen soon after a processed meat meal compared to a vegetarian meal. 

This study compared the effects of a processed meat-based meal and a vegetable-based meal on glucose, insulin, and gastrointestinal (GI) hormone (hormones that control the appetite, emptying of the stomach, insulin and glucose release) levels. 97 subjects were included in the study (48 type 2 diabetics and 49 healthy subjects).

Each subject completed two study visits. Before each visit they did not eat or drink for 10 to 12 hours (fasting). At one visit they ate a meat-based meal (a fast-food cheeseburger) and at the other they ate a vegetarian meal (a burger made from couscous). Calorie (energy) levels were similar between the meals but the vegetarian meal had 25% more carbohydrates. The meat-based meal had 10% more protein and 15% more fat. Glucose, insulin and GI hormones were measured after each meal.

After fasting diabetic subjects had higher levels of blood glucose and insulin than healthy subjects. The changes in glucose were similar after both meal types for both diabetic and healthy subjects. However, after the vegetarian meal the highest levels of blood glucose occurred after 30 minutes for healthy subjects and after 60 minutes for diabetic patients.

Both meal types caused a significant increase in insulin. In diabetic subjects insulin levels continued to increase for longer than healthy subjects after both meal types. The high levels of insulin lasted longer after the meat-based meal than the vegetarian meal for both diabetic subjects and healthy subjects.

Fasting levels of GI hormones were higher in diabetic subjects than healthy subjects. GI hormone levels were significantly lower for healthy subjects following the vegetarian meal compared to the meat-based meal. Diabetic subjects saw the opposite: GI hormone levels were significantly higher following the vegetarian meal.

This study concluded that all parts of the diet, not only carbohydrate counts, are important in managing the diet of type 2 diabetes patients. 

Please consult with your doctor if you are unsure of how to best manage your diet to control your diabetes.