PHILADELPHIA – Weight loss is the cornerstone of lifestyle measures to prevent people with prediabetes from progressing to type 2 diabetes, but other dietary steps also help, according to draft recommendations from a working group of the Academy of Nutrition and Dietetics.
In addition to weight loss, the new recommendations call for a registered dietician nutritionist to provide medical nutrition therapy to people with prediabetes and to produce individualized plans for macronutrient distribution, Patricia Davidson, DCN, said at the annual meeting of the American Association of Diabetes Educators.
Mitchel L. Zoler/IMNG Medical Media
Dr. Patricia Davidson (left) and Shelley Mesznik
"A registered dietician nutritionist and certified diabetes educator who provides medical nutrition therapy as part of a diabetes management team plays an important role in preventing onset of type 2 diabetes," said Dr. Davidson, who practices in Westfield, N.J., and chaired the panel that drafted the recommendations.
The finalized, published version is planned for later this year, she said.
The draft recommendations also call for an attempt at reducing a person’s glycemic index and glycemic load. "Reducing glycemic load may or may not help, but it can’t hurt, so we try it," said Shelley Mesznik, a member of the recommendation panel and a registered dietician and certified diabetes educator in Mount Kisco, N.Y.
In addition, the recommendations call for consumption of vegetable protein rather than animal protein for prevention of diabetes, but say there is no evidence that the amount of particular fat types in the diet affects progression to diabetes. The recommendations say that while evidence supports physical activity as a means to prevent progression to metabolic syndrome (when done for 135-180 min/week), there is no documented effect of activity on development of diabetes.
Despite endorsing medical nutrition therapy, both speakers highlighted the primacy of weight loss, achieved by lifestyle modification or bariatric surgery.
"We definitely found that weight loss is the key," said Dr. Davidson.
"If a patient asks for a number, we say aim to lose 10%-15%, but we’re looking for trends in the right direction; loss is more important than the size of the loss," Ms. Mesznik said.
The recommendations specify that several of the more marginal interventions, such as reduced glycemic load and index, use of vegetable protein, and increased physical activity, have evidence for efficacy only in the context of concurrent weight loss.
The panel performed a literature review to determine whether diet can reduce the risk for development of type 2 diabetes. The evidence summaries drawn from this literature that form the bases for the recommendations are available only to members of the Academy of Nutrition and Dietetics, Dr. Davidson said.
The work group also addressed the definition of people at high risk for diabetes, and discussed the differences between patients at risk because of prediabetes – based on fasting or challenged glucose levels or blood level of hemoglobin A1c, and those at risk with metabolic syndrome. Most interventions discussed appear equally effective in both populations, except for exercise, which is more effective for metabolic syndrome.
The panel also commented on the growing prevalence of prediabetes. In 2010, the Centers for Disease Control and Prevention estimated that 79 million Americans aged 20 or older had prediabetes, which included about half of those aged 65 or older, said Ms. Mesznik. In 2009, the CDC estimated that about a third of Americans aged 20 years or older had metabolic syndrome.
Dr. Davidson and Ms. Mesznik had no disclosures.
On Twitter @mitchelzoler