Nutrition Therapy for Adults With Diabetes or Prediabetes

Anne L. Peters, MD


June 25, 2019

Hi. Today I'm going to discuss the new guidelines for nutrition therapy for adults with diabetes or prediabetes.[1] Although I'm going to discuss the findings in this consensus report, I urge you to read it, because more than any other guideline on nutrition, they really go through all of the different studies and discuss all of the conclusions.

We know that medical nutrition therapy is very effective at lowering A1c levels, so it can work as well as medication. But the problem is getting people to change their habits and then stick to a new way of eating long-term. I don't like to call this a diet. What we call it is a lifestyle change—a form of eating and a way of existing that is healthier than prior patterns.

It is recommended that adults living with either type 1 or type 2 diabetes have individualized diabetes-focused medical nutrition therapy, both at diagnosis and then as needed throughout life. People really do need refreshers, and it helps to encourage them to see their registered dietitian as they live their life with diabetes.

In general, it's recommended that the focused medical nutrition therapy be given by a registered dietitian who has expertise in this field, particularly for patients with diabetes. It's also recommended that patients with prediabetes with overweight or obesity be introduced to lifestyle interventions such as the Diabetes Prevention Program, which are becoming increasingly more available to our patients.

Primary Goals of Nutrition Therapy

The primary goals of nutrition therapy are to promote and support healthful eating patterns, emphasizing a variety of nutrient-dense foods in appropriate portion sizes. This will lead to improvements in A1c levels, blood pressure, and cholesterol levels.

A second and very important goal is to maintain the pleasure of eating for patients by giving them positive messages about healthy food choices, and to provide practical tools for day-to-day meal planning.

Evidence suggests that there is not an ideal percentage of calories we should be consuming from carbohydrate, protein, and fat. Instead, macronutrient distribution should be based on individualized needs, using current eating patterns, preferences, and metabolic goals.

A key strategy to achieving this is for patients to undergo an assessment of what they're currently eating, followed by individualized guidance on self-monitoring of carbohydrate intake and optimizing meal timing, food choices, medication, and physical activity. In general, a variety of eating patterns are acceptable for the management of diabetes. There isn't just one way, but the best way is the one that the patient will adhere to.

Key Patterns to Emphasize

What's most important is that we focus on these key patterns. First, emphasize nonstarchy vegetables, but remember that vegetables in general are good for you. Second, minimize the use of added sugars and refined grains. And third, choose whole foods over highly processed foods. This is pretty simple.

Reducing overall carbohydrate intake has demonstrated the most evidence for improving glucose control. A low- or very-low-carbohydrate eating plan is, in fact, a viable approach for the management of patients with diabetes. The eating patterns with the most robust research on prediabetes or type 2 diabetes prevention are Mediterranean, low-fat, or low-carbohydrate eating plans.

Many different eating patterns are discussed in this consensus statement, including Mediterranean; vegetarian or vegan; low-fat; very-low-fat, such as Ornish or Pritikin; low- or very-low-carbohydrate; DASH; Paleo; or intermittent fasting. All of these are acceptable as long as the patients are getting the right distribution of macro- and micronutrients to stay healthy and achieve their target goals.

In individuals with type 1 diabetes, a very-low-carbohydrate eating pattern may have potential benefits, but we don't have clinical trials of sufficient size and duration to confirm the findings from prior smaller studies.

Sugar-sweetened beverages are not good. We all know that. They are associated with an increased risk for type 2 diabetes, weight gain, heart disease, kidney disease, nonalcoholic fatty liver disease, and tooth decay. We want patients to consume water, as much as they can, as a replacement for these sugar-sweetened beverages.

Sugar substitutes are "less bad" than the sugar-sweetened beverages, but they are not considered "good." Patients should avoid compensating with sugar substitutes as much as they can because they're going to potentially increase caloric intake from other food sources.

Other Considerations

Overall, it is not recommended that patients take vitamin or mineral supplements unless they're proven deficient. There needs to be a consideration of patients having additional vitamin B12 supplementation if they're on metformin, so it's recommended that vitamin B12 status be assessed annually in patients who take metformin.

In terms of fat and reducing risk for cardiovascular disease, it is recommended that saturated fat be kept to less than 10% of the overall diet, regardless of whether it's a high-fat or low-fat diet. If patients are adding in more fat to their diet, it should be unsaturated fat.

Recommendations for sodium intake are the same as for the general population. In general, patients with diabetes do not need sodium restriction.

Interestingly, it is no longer recommended that we reduce protein intake in patients with chronic kidney disease. In fact, the report states that protein intake doesn't need any restriction compared with what we recommend for the general population. However, those with macroalbuminuria may benefit from switching to soy-based protein to reduce their risk for cardiovascular disease.

In conclusion, people with diabetes should work with a registered dietitian to create an appropriate and acceptable way of eating. It's important to realize that there's no single way to do this. In fact, the way patients eat may change over time.

I'm not a huge fan of fads. I think there are many different approaches to healthy eating. With the right help and advice, it's possible to create an eating plan that will work for most of your patients with diabetes. Thank you.


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