Obese? Here’s What You Really Should Know About Mediterranean Diet to Lower Your Risk of Diabetes

Carrying excess weight or living with obesity can lead to a host of related health issues, including but not limited to, heart disease, type 2 diabetes (T2D), various cancers, abnormal cholesterol levels, and high blood pressure.

Insulin resistance (IR) plays a significant role in exacerbating complications associated with obesity, and it also serves as a risk factor for cardiovascular issues, even in individuals without T2D.

Research indicates that potentially over one-third of the adult population might be on the brink of developing diabetes, yet a large number of these individuals might be unaware of their vulnerability to the disease.

This highlights the urgency for timely identification and management of IR and prediabetes, as these are crucial steps in preventing further cardiometabolic health issues.

Various factors can precipitate the onset of IR or prediabetes. These include poor dietary habits, a genetic predisposition to T2D, excessive body fat, and a sedentary lifestyle. Addressing these issues through lifestyle modification stands out as a primary strategy for safeguarding against the onset of prediabetes and IR.

Commitment to the Mediterranean diet (MD) has been linked to a diminished risk of T2D. Specifically, a meta-analysis has shown that for every two-point increase in adherence to the MD, there is a 14% reduction in the risk of T2D.

The MD is distinguished by its emphasis on regular consumption of plant-based foods, extra-virgin olive oil, moderate intake of animal fats and proteins, and a limited intake of processed foods and sweets.

However, it is still a subject of ongoing research and debate as to whether the health benefits attributed to the MD are the result of the diet in its entirety or due to specific elements within the diet.

In a recent investigation featured in the journal Nutrients, scientists explored the relationships between commitment to the Mediterranean Diet, along with insulin production, resistance, and responsiveness in individuals who are overweight or dealing with obesity.

The current research scrutinized the links between adherence to the MD, insulin resistance (IR), insulin secretion (IS), and various indices of insulin sensitivity in individuals who are either overweight or obese. The investigation was carried out at a university hospital’s obesity center in Italy, with participant screening occurring from January 2022 to January 2023.

Adults aged 18-65, boasting a body mass index (BMI) above 27 kg/m^2 and maintaining a stable body weight for the prior three months, were considered eligible.

Exclusion criteria for the study included being pregnant or lactating, having type 2 or type 1 diabetes, cerebrovascular or cardiovascular diseases, cancers, chronic inflammatory conditions, or liver/kidney failure.

Those on medications such as glucose-lowering therapy, antipsychotic drugs, glucocorticoids, glucagon-like peptide 1 (GLP1) receptor agonists, or any that contribute to weight gain were also omitted from participation.

Participants were required to share details about their demographics, lifestyle habits, and medical history, in addition to their adherence to MD, which was assessed using the 14-item PREDIMED questionnaire. An oral glucose tolerance test was administered to measure plasma insulin and glucose levels.

Fasting indices were evaluated using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), while IS capacity was assessed through HOMA for β-cell function. Post-glucose load insulin activity was gauged using the Insulin Sensitivity Index (ISI) and Oral Glucose Insulin Sensitivity (OGIS) method.

The study deployed Pearson’s or Spearman rank correlation to delve into the relationships between various study variables.

A total of 62 participants, average age of 49 years and predominantly female (55 participants), were involved in the study, with an average BMI of 35.8 kg/m^2. The cohort was categorized based on their MD adherence levels: 12 with low, 35 with intermediate, and 15 with high adherence.

Older individuals tended to show higher adherence to MD. Across these groups, no significant differences were noted in terms of lifestyle habits, disease prevalence, BMI, or gender distribution.

Similarly, concentrations of glycated hemoglobin (HbA1c), and the prevalence of impaired fasting glucose and impaired glucose tolerance, were consistent across the adherence groups.

While fasting plasma glucose levels were comparable across all groups, those with high MD adherence exhibited significantly reduced fasting insulin levels. These individuals also had lower HOMA-IR scores and showcased enhanced insulin sensitivity compared to the other groups.

The high adherence group, however, displayed a reduced β-cell function when compared to the intermediate adherence group, though no difference was found when compared to the low adherence group.

The score derived from the PREDIMED assessment demonstrated a positive relationship with the Insulin Sensitivity Index (ISI) and a negative association with the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR).

In terms of specific components of the Mediterranean Diet, the consumption of fish exhibited a direct link with ISI, while it was inversely related to both HOMA-IR and β-cell function. These relationships maintained their significance even after making adjustments to Body Mass Index (BMI).

The study concluded that high adherence to the Mediterranean Diet, especially with increased fish consumption, is associated with reduced insulin resistance during fasting and post-glucose load in individuals who are overweight or obese.

These findings underscore the clinical significance of lifestyle modifications as a preventative approach to diminish the risk of prediabetes and insulin resistance complications.

However, the study’s cross-sectional nature is a limitation, preventing the establishment of a causal relationship.

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