Low-GI Mediterranean Diet Enhances Quality of Life for Diabetes-Prone Adults: Study

In a recent study published in The Journal of Nutrition, researchers explored the effects of low- and high-glycemic-index (GI) Mediterranean-style (MED) healthy eating patterns (HEPs) on sleep and health-related quality of life.

Health-related quality of life strongly predicts morbidity and mortality, making it a crucial measure for evaluating the effects of interventions. Evidence indicates that low HRQoL is associated with higher cardiometabolic risks. The 36-item short-form health survey (SF-36) is commonly used to assess HRQoL. Additionally, sleep is an important lifestyle factor linked to both cardiometabolic health and HRQoL.

The glycemic index (GI) of food indicates its carbohydrate quality, with glycemic variability reflecting blood glucose fluctuations. Researchers previously reported that the GI of a Mediterranean-style healthy eating pattern (MED-HEP) influences glycemic variability and postprandial glucose response.

Researchers investigated the effects of low- and high-GI Mediterranean-style healthy eating patterns (MED-HEPs) on sleep and health-related quality of life (HRQoL) in individuals with metabolic syndrome.

Participants followed a controlled weight-maintenance diet based on MED-HEPs, with either high or low GI, for the intervention period. Sleep and HRQoL were assessed using questionnaires at baseline and during the final two weeks of the intervention. During the baseline period, participants consumed their regular diets. Both groups had identical fibre and carbohydrate amounts, but the GI differed due to variations in starch sources.

The results showed that 57% of participants had poor sleep quality, and 18% reported excessive daytime sleepiness. Both groups increased their intake of protein, fiber, carbohydrates, and energy, while reducing fat and alcohol consumption. The intervention led to HRQoL improvements, particularly in the role of physical and vitality domains for the low-GI group. No significant differences were found between the groups in other HRQoL domains.

Both groups showed improvements in general health and vitality from baseline to post-intervention. Sleep quality did not differ significantly between groups, although both experienced better sleep latency and reduced daytime dysfunction.

The findings revealed that a low-GI MED-HEP resulted in modest improvements in specific HRQoL domains, such as vitality and physical role, relative to a high-GI MED-HEP; furthermore, there were no significant differences in sleep indices between groups.

Reference: Hjort A, Bergia RE, Vitale M, et al. Low- vs high-glycemic index Mediterranean-style eating patterns improved some domains of health-related quality of life but not sleep in adults at risk for type 2 diabetes: The MEDGICarb randomized controlled trial. The Journal of Nutrition, 2024, DOI: 10.1016/j.tjnut.2024.07.005, https://www.sciencedirect.com/science/article/pii/S0022316624003857