Effects of mediterranean-type diet and low-fat diet on intestinal permeability, anthropometric measurements and biochemical parameters in obese women

Obesity is known to be a major risk factor for various diseases such as diabetes, hypertension, dyslipidemia, cardiovascular diseases and many types of cancer. Many popular diets with different macronutrients, including the Mediterranean diet, have been preferred, recommended and studied for the prevention and management of obesity. This study was conducted to examine the effect of dietary fat pattern and amount on intestinal barrier function and to determine the effect of the Mediterranean diet and low-fat diet approaches on weight loss and biochemical parameters. The sample of the study was conducted with 24 female individuals, aged 19-55 years, with a Body Mass Index (BMI) between 30.0-34.9 kg/m2, who applied to the Ordu University Health, Culture and Sports Department Diet Clinic between January 2023 and December 2023 and accepted to participate in the study voluntarily. A questionnaire form was applied to determine the socio-demographic characteristics, general health status and nutritional habits of the individuals. At the beginning of the study, the nutritional status of the women was determined using the 24-hour reminder method. In order to determine the physical activities of the individuals, the International Physical Activity Questionnaire Short Form (IPAQ Short Form) was applied. Individuals who met the inclusion criteria were administered the Mediterranean Diet Adherence Scale (MEDAS) before the study, and individuals who scored <7 on the scale were included in the study. Participants were randomly assigned to groups based on this result; Mediterranean diet and low-fat diet groups were formed. Individual diet planning was applied to individuals in both groups, depending on the characteristics of the group they were in, and it was aimed for individuals to lose an average of 10% of their initial body weight at the end of an average of 12 weeks. Body composition analyses, anthropometric and biochemical measurements of both groups were repeated at the beginning of the study and when an average of 10% weight loss was achieved. The difference in BMI values, waist-hip and waist-height ratios, body fat mass and serum fasting insulin averages of both groups before and after the diet was found to be statistically significant (p<0.05). However, when the first and last measurements were compared between the groups, the difference between them was not found to be significant (p>0.05). The decrease in Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) and serum ALT values in the Mediterranean diet group was found to be statistically significant (p<0.05). The change in the mean serum zonulin level of women in both diet groups before and after the diet was not found to be statistically significant (p>0.05). The change in CRP (C-reactive protein) levels before and after the diet was not found to be statistically significant in both diet groups (p>0.05). In individuals on the Mediterranean diet, a negative and significant relationship was found between triglyceride and zonulin before the diet (r=-0.582; p=0.047). In women on a low-fat diet, a negative and statistically significant relationship was found between waist height ratio and low-density lipoprotein (LDL) cholesterol after the diet (r=-0.653; p=0.021). In women on the Mediterranean diet, a positive and statistically significant relationship was found between serum AST and BMI after the diet (r=0.802; p=0.002). In the Mediterranean diet, a positive and statistically significant relationship was found between waist height ratio and AST before the diet (r=0.599; p=0.040). In this group, a positive and statistically significant relationship was found between waist height ratio and triglyceride after the diet (r=0.699; p=0.011). As a result; no statistical significance was found in serum zonulin values of both diet models before and after the diet. In individuals taking the Mediterranean diet, a negative significant relationship was observed between triglyceride and zonulin before the diet (r=-0.582; p=0.047). The relationship between these variables was not found to be significant after the diet (r=-0.441; p=0.152). This study shows that both low-fat diet and Mediterranean-type nutrition can be effective in improving obesity. However, more studies are needed to observe their effects in the long term.