Nutritional interventions for type 2 diabetes management with glycemic control

By Dr. Liji Thomas, MDReviewed by Benedette Cuffari, M.Sc.May 6 2024

Poor nutrition is fundamental to most lifestyle diseases, including type 2 diabetes mellitus (T2DM). Therefore, adopting a healthy and nutritious diet can be pivotal for treating these patients and preventing further complications.

A recent study published in Nutrients explores the effects of healthy diet interventions on various body mass and cardiometabolic parameters.

Study: The impact of a nutritional intervention on glycemic control and cardiovascular risk markers in type 2 diabetes. Image Credit: Pixel-Shot / Shutterstock.com

T2DM and obesity

T2DM remains a major public health issue throughout the world, as it affects nearly 540 million people between 20 and 80 years of age. The high prevalence of T2DM can be attributed to the aging global population and deterioration of modern lifestyles.

Simultaneously, the prevalence of obesity and overweight has also risen throughout the world, with about 700 million and 2.3 billion people considered obese and overweight, respectively. Obesity predisposes individuals to T2DM, both of which increase the risk of cardiovascular disease (CVD).

Prior research has demonstrated the anti-inflammatory and fat loss benefits of caloric restriction. This dietary approach can also increase leptin sensitivity, modulate the composition and metabolite profile of the gut microbiota, and enhance metabolically active brown fat formation.

Dietary intervention in T2DM

A nutritional re-education based on the importance of the balance of concentrations of fats, carbohydrates, and proteins to control T2DM.”

Various dietary interventions have been proposed for the management of T2DM. Importantly, these diets should adapt to individual preferences and culture, as well as financial constraints. Self-monitoring and supervision is also crucial to promote careful observation of glycemic parameters, which will be used to adjust the intervention and improve adherence.

An interdisciplinary approach may be optimal for achieving long-term success. For example, multiple strategies can be used that incorporate culturally sensitive language and media, encourage physical exercise, promote medication compliance, and change the food spectrum as indicated.

Both the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets have been shown to be protective against cardiometabolic disease and mental illnesses. These diets offer a wide variety of foods that are palatable and consistent with improved overall health, while also being compatible with long-term continuance. Nevertheless, these diets must be adapted to local food cultures and economies.

Taken together, simple lifestyle modifications are essential to the successful management of T2DM. These include eating slowly, chewing properly, timing meals correctly, sufficient sleep, and walking for health after a meal.

About the study

The current study is a preliminary attempt to establish the clinical value of specific dietary interventions in diabetes. Moreover, the current study was conducted in Brazil, wherein 60% and 25% of its population is considered overweight and obese, respectively, along with about 16 million diabetes patients.

The non-randomized non-blinded experiment involved a total of 84 diabetic participants, 44 of whom received the treatment and 40 served as controls. Diabetic patients were between 18 and 80 years of age.

All study participants received baseline medical care; however, the treatment patients also received dietary evaluation at quarterly intervals. Each consultation included six to nine patients.

Study participants were advised to choose and personalize diets roughly corresponding to locally modified Mediterranean or DASH diets. A follow-up session was conducted at 15 months.

What did the study show?

Blood glucose levels in the treatment group reduced from the third month onward, with sustained effects at the follow-up visit. In controls, blood glucose levels rose from the first to the ninth month and remained elevated at the follow-up visit.

For controls, blood sugar control worsened, as reflected by rising hemoglobin A1c (HbA1c). In the treatment group, HbA1c levels declined between the first and third months and remained stable at lower levels until the follow-up visits.

While weight gain and higher body mass index (BMI) values were observed in the control group, body weight was reduced by about 11% in the treatment group from the beginning of the experiment. Waist circumference and waist-to-hip ratio (WHR) were reduced in the intervention group throughout the study period.

Weight loss by 5-7% can normalize or markedly reduce blood glucose levels in T2DM patients. Therefore, the weight loss observed in the current study reflects the long-term utility of nutritional interventions for this condition.

No significant changes in cholesterol levels were observed in the treatment group, whereas cholesterol levels rose from the sixth to fifteenth month in the control group. Low-density lipoprotein (LDL) and triglycerides, both of which are important CVD risk markers, reduced only in the sixth month in the controls but remained significantly reduced from the first to the third month onwards until the follow-up visit.

Differences in blood pressure levels were observed between the groups from early in the study until the follow-up visit. A significant reduction in heart rate was also observed from before the third month until follow-up.

Thus, the dietary intervention was associated with significantly improved results in all parameters as compared with controls. These differences persisted at end of the study, with the exception of an increase in BMI in both groups.

Importantly, the type of diet habitually consumed changed significantly in the treatment group. From high-carbohydrate, sweetened, and highly processed foods, as well as poor money management, patients in the treatment group began to eat more fresh or minimally processed foods and less ultra processed foods. Home cooked meals were also prepared and eaten more frequently as compared to baseline levels in this group; however, any changes in dietary habits were not recorded for controls.

Conclusions

It is extremely important that nutritional management is inserted into lifestyle change programs, especially in the context of public health, aiming to optimize and sustain results in the long term.”

With individualized nutrition leading to better eating habits, improvements in body mass parameters, cardiovascular markers, and biochemical values were observed in patients with T2DM throughout the study period. These sustained results at follow-up could be attributed to the broad range of foods permitted, including carbohydrates like rice and beans, which are prohibited in many popular diets.

Both the Mediterranean and DASH diets were popular with the intervention group, as they can be customized to accommodate cultural and financial considerations. Nevertheless, monitoring and re-education are crucial to raising and sustaining awareness about the health, financial, and social impact of food choices.

Consistent monitoring and personalized nutritional management are essential for optimizing long-term outcomes…Once informed and aware, individuals will have complete autonomy to make more informed choices to acquire foods of higher nutritional quality.”

Due to the non-randomized nature of the current study, additional well-designed clinical trials are needed to validate these findings and provide more generalizable results.