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Certain types of diets may affect insulin resistance and weight loss results for people with diabetes. Design by MNT; Photography by Jenny Dettrick/Getty Images & Elizabeth Fernandez/Getty Images
  • Type 2 diabetes is a chronic disorder influenced by diet and other lifestyle factors.
  • People with diabetes can work with nutritionists and other specialists to develop meal plans that are diverse and nutritious.
  • One food that nutritionists may ask people with diabetes to initially stay away from or lower their consumption of is carbohydrate-rich foods such as potatoes.
  • Data from a recent study, however, found that low-energy bean and potato-based diets may be effective in helping reduce insulin resistance and promoting weight loss.

Diet is an essential component of health, particularly for people with diabetes or who are more at risk of developing diabetes. Researchers are constantly examining how food choices can impact people in this demographic.

A​ recent study published in the Journal of Medicinal Food explores how potato and bean diets may help people who are insulin-resistant.

The researchers found that participants consuming a diet rich in beans and potatoes experienced weight loss and reduced insulin resistance.

it is important to note that the study received funding from the Alliance for Potato Research and Education.

Type 2 diabetes (T2D) is a chronic condition where the body does not respond to insulin normally. Insulin is a critical component that enables the body’s cells to use glucose for energy.

People who are at risk for diabetes and people with type 2 diabetes can follow eating plans that help them manage their diabetes and improve their physical well-being. Each person will have slightly different needs, but organizations such as the Centers for Disease Control and Prevention (CDC) offer some general recommendations.

For example, some people with type 2 diabetes should limit carbohydrates and increase their intake of non-starchy vegetables. Starchy vegetables such as beans and potatoes contain carbohydrates, but that doesn’t mean people with diabetes or insulin resistance must eliminate them completely.

Registered dietitian nutritionist Yelena Wheeler, who was not involved in the study, explained to MNT:

“Potatoes and beans are not innately ‘bad foods’ when it comes to glucose management. However, preparations of these foods can determine how beneficial or detrimental these foods can be to one’s glucose management.”

“Additionally, not all potatoes are created equal. Sweet potatoes and yams baked with the skin on can, in fact, be great additions to a well-balanced diet by providing its high fiber content,” she said.

“Fiber content contributes to satiety and blood sugar management. This, in turn, can decrease a person with [type 2 diabetes] dependence on insulin and, therefore, may also improve weight maintenance and even weight loss,” Wheeler explained.

T​his particular study was a randomized feeding equivalence trial. It included 36 adult participants with insulin resistance.

Researchers compared two diets: one high in potatoes and the other in pulses (beans and peas) and the diets’ impact on blood glucose control. Participants were on one of the two controlled diets for eight weeks with regular follow-ups.

Kristian Morey, registered dietitian, and clinical dietitian with the Nutrition and Diabetes Education program at Mercy Medical Center in Baltimore, who was also not involved in the study, noted to MNT:

“One interesting detail that they mention in the study was that they cooked and cooled the potatoes prior to serving them to participants. This process can make some of the starch contained in the potato slower to digest than before, and this can improve insulin sensitivity and glucose tolerance when consuming such food.”

“It is also important to note that they consumed other foods—such as protein foods—with the potatoes, which can improve glycemic response as well,” she added.

Overall, the researchers found that participants on both diets did not see a significant drop in blood glucose levels. However, both groups experienced weight loss and reduced insulin resistance.

Amy Kimberlain, registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics Media, who was not involved in the study, told MNT:

“This study helped show that utilizing foods that reduce the energy density of the diet will not only allow for an improved insulinemic response but also help to promote weight loss as well.”

“Additionally, this study helps to continue the conversation that we can improve different risk factors in people by making changes in our diets (eating patterns) but still continue to eat foods that we enjoy.”
— Amy Kimberlain

The study did have several limitations. First, it included a small sample size, so future studies can work on including more participants. Most participants were female, indicating more diverse follow-up may also be needed.

The study was also only eight weeks long, so more long-term studies are required to look at long-term results.

The researchers noted that the differences between participants’ baselines of Body Mass Index (BMI) and fasting insulin levels did ultimately affect the study’s outcomes. There were also some difficulties in study completion due to the COVID-19 pandemic.

Kimberlain also noted that researchers had tight control over food preparation but that translating this into real-life practice could be more difficult.

“These meals were prepared for the people in a metabolic kitchen, meaning the ability to confirm what people were eating (calories/content/etc.) was there. And while this is a study and they used this to have the ability to confirm intake, to verify and/or see if this is effective in the long-term with people, it’d be important for people to be able to do this on their own (after receiving instruction on how to prepare the examples of meals they received),” she said.

Overall, the study demonstrates that preparation and food choices are essential components of diabetes control. Further research is warranted to confirm how starchy vegetables like beans and potatoes can contribute to healthy diets for people at risk for type 2 diabetes.