What’s the Best Diet for Diabetes?

Searching for info on what to eat if you have diabetes? Many people are surprised to find that there is no “diabetic diet,” or an exact eating prescription. In fact, the American Diabetes Association (ADA) advises that “many different meal plans” can be used to manage diabetes, including the Mediterranean Diet, the DASH diet, a vegetarian or vegan diet, a low-carb diet or low-fat diet. While the flexibility is nice, it also can leave you frustrated and not knowing where to even begin.

So, what’s the best diabetic diet? Here are five eating approaches, and how they may impact diabetes, weight, and long-term health, based on current research.

The Mediterranean Diet was patterned after traditional diets in countries like Italy and Greece after researchers discovered the lower incidence of chronic disease in those areas. The eating approach places a heavy emphasis on plants foods, whole and minimally processed foods, and healthy fats.  Foods that are to be greatly limited or avoided are red meat, added sugars, processed foods, and refined grains.

• Numerous studies suggest that following the Mediterranean diet reduces A1C levels, improves fasting glucose levels and insulin sensitivity, supports weight loss, and reduces cardiovascular risk. Following the diet is also associated with significantly reducing the likelihood of developing Type 2 diabetes.
• In an analysis that included almost 3500 Type 2 diabetics on six different diets, those following Mediterranean diets and low-carb diets had the greatest weight loss, and some of the most promising results for A1C levels and weight loss came from following a low-carb Mediterranean diet where less than 50 percent of calories come from carbohydrates.

The eating approach does not specify calorie levels or daily serving size amounts, so overall moderation of calories and carbohydrate intake is necessary.

The DASH diet was designed to treat hypertension and emphasizes foods that are naturally low in sodium, high in potassium, and high in fiber (vegetables, fruits, and whole foods). Serving sizes from each food group are provided based on individual calorie needs. The emphasis on plant foods and minimal processing makes it similar to the Mediterranean Diet. Processed foods and foods high in sodium, added sugars, trans fats, and saturated fats are severely limited on this diet.

• Heart disease is a leading cause of death for Type 2 diabetics, and research suggests the DASH Diet is effective in lowering blood pressure in those with diabetes and may possibly aid in improving blood lipids.
• There is strong research to suggest that following the DASH diet may reduce ones risk of developing prediabetes or Types 2 diabetes.

• The eating approach is higher in carbohydrates than most others included in this article, and some diabetics may find the approach too high in carbohydrates for their condition.
• Even though the DASH diet is nutrient-dense and may prevent the development of Type 2 diabetes, there’s little research to suggest that following it provides effective glucose management in diabetics.

Vegetarian diets rely on plant foods (vegetables, fruit, nuts, seeds legumes, soy, etc.) to meet energy and nutrient needs. Some milk, dairy products, eggs, and sometimes even fish may be included, depending on the type of vegetarian diet followed. A vegan diet is the strictest type of vegetarian diet since it means avoiding all animal products.

• Research suggests that following a plant-based diet may improve insulin sensitivity, improve blood glucose control, potentially reduce the risk of developing type 2 diabetes, and may allow for diabetic medications to be reduced. Those following vegan diets typically see the greatest improvements.
• Most plant-based diets result in significantly higher fiber intake, which appears to improve glycemic response and provide satiety levels to aid in weight loss. Individuals following a plant-based diet are at significantly lower risk for developing Type 2 diabetes.

• Getting adequate protein to provide satiety may result in higher carbohydrate intakes, since vegetarian protein sources such as legumes, peas, whole grains, nuts, seeds, and soy are also composed of carbohydrates.
• “Vegetarian” or “vegan” doesn’t necessarily mean healthy; there are a lot of less healthy processed food products that are vegetarian or vegan that contain added sugars and less healthy fats.

The Paleo Diet is based on the idea that to achieve optimal health and prevent disease, one should mimic the diet eaten thousands of year ago. This means a diet of local, grass-fed animal proteins, organic vegetables and fruits, nuts, seeds and oils and fats such as coconut oil, olive oil, flaxseed oil, and avocado. Foods that are to be greatly limited or avoided include legumes, grains, dairy products, potatoes, processed foods, refined vegetable oils, added sugars and alcohol.

• While there are very few studies looking specifically at the Paleo Diet, research suggests that following the eating approach may lower A1C, triglycerides, and blood pressure, and be an effective way for Type 2 diabetics to lose weight.
• Paleo diets are centered around whole, less processed foods and foods with a lower glycemic index, and are typically lower in carbohydrates when compared to the Mediterranean Diet, the DASH Diet, and vegetarian diets—something that some diabetics may find key in their glucose management.  

• The diet focuses on food quality, but not quantity, so overall moderation of calories and carbohydrates is necessary.
• The diet is typically above protein recommendations, and excess protein consumption is something health professionals have worried about having negative effects on kidney function. More recent research suggests that higher protein intakes does not impact kidney function in healthy adults, only those with kidney issues.

Typically, most low-carb diets—such as Atkins—refer to consuming less than 30 percent of your daily calories from carbohydrates, which means primary foods eaten are non-starchy vegetables, animal proteins, dairy products, nuts and seeds, and oils and fats such butter, avocado, and oils. Any foods with more than 5g carbs should be greatly limited, which include starchy vegetables, legumes, grains, and fruits, as well as processed foods with added sugars.

Effects on Diabetes

• Numerous studies suggest that a low-carb diet decreases fasting glucose, A1C, and triglycerides. In fact, a group of 26 physicians and researchers from around the country published a summary of research in 2015 to advocate that carbohydrate restriction be used as the primary focus of type 2 diabetes treatment and prevention.
• Another review of studies using low-carb diets to manage diabetes found that weight loss was an effect seen in all, and the loss was primarily attributed to fat loss, not water loss. Also, no negative effects were seen in cardiovascular risk factors.

• There is no exact definition for a “low-carb diet” and no ideal carb intake established for this eating approach.
• Less is known about “very low-carb diets” that refer to eating only 5-10 percent of calories from carbs such as the keto diet; research to-date has been mixed. Suddenly cutting out a significant amount of carbs could cause hypoglycemia for diabetic individuals on insulin or other medications.
• Low-carb diets are often higher in fat and protein. As mentioned above with the Paleo Diet, consuming higher protein appears to be safe for healthy individuals, but not those with kidney disease.  Also, since animal protein is often the main source of protein, it is important to watch saturated fat intake to minimize cardiovascular risks.

All five diets appear to be more effective than a low-fat approach when it comes to managing blood glucose and losing weight, and the Mediterranean Diet, vegetarian diet, and low-carb diet had the most research to support usage for Type 2 diabetes management and/or prevention.

However, some of the most impressive findings came when a low-carb Mediterranean diet combination was used suggesting that a less processed, more plant-forward eating approach with healthy fats and moderate to low carbs intake may be hold the most promise for improvements.