Italian Ketogenic Mediterranean Diet in Overweight and Obese Patients with Prediabetes or Type 2 Diabetes

Abstract

Obesity is a multifactorial disease strongly associated with insulin resistance and/or type 2 diabetes mellitus. Correct nutrition represents a valid strategy to fight these dysmetabolic pathologies responsible for numerous diseases, including inflammatory and cardiovascular ones. Medical nutrition therapy, including a Mediterranean diet (MD) and a very low-calorie ketogenic diet (VLKCD), is the first-line treatment for prediabetes/diabetes and overweight/obesity. Eighty patients (forty women and forty men) affected by overweight/obesity and type 2 diabetes mellitus or impaired glucose tolerance or impaired fasting glucose (51 (ys) ± 1.75; BMI (kg/m²) 33.08 ± 1.93; HA1c (%): 6.8% ± 0.25) were enrolled at the University Service of Diet Therapy, Diabetology and Metabolic Diseases, Policlinico Riuniti Hospital of Foggia, and subjected to a very-low-calorie Mediterranean diet and a very-low-calorie ketogenic Mediterranean diet for thirty days. Both diets result in a marked decrease in body weight (kg) and BMI (kg/m²). At the same time, only the very-low-calories ketogenic Mediterranean diet reduced waist and hip circumferences. Both diets helped reduce fat mass, but a major loss was achieved in a very low-calorie ketogenic Mediterranean diet. Among gluco-metabolic parameters, only the very-low-calorie ketogenic Mediterranean diet group showed a significant decrease in fasting blood glucose and HbA1c, insulin, C-peptide total cholesterol, LDL, and triglycerides. The results of our study seem to show that the very-low-calorie ketogenic Mediterranean diet is a good strategy to improve rapidly metabolic, anthropometric, and body composition parameters in patients with prediabetes or diabetes and overweight/obesity.

Keywords: Mediterranean diet; VLCD_MED; VLCKD_MED; obesity; overweight; prediabetes; type 2 diabetes.

Figure 1

VLCKD_MED: very-low-calorie ketogenic Mediterranean diet and VLCD_MED: very-low-calorie Mediterranean diet.

Figure 2

Percentage change of the anthropometrical and body composition variables after VLCKD_MED and VLCD_MED diet. The histogram depicts the % change (post-pre diet) in the level of weight (kg), BMI: body mass index (kg/m²), FM: fat mass (kg), FFM: free fat mass (kg), TBW: total body water (kg), CV: waist circumference (cm), CF: hip circumference (cm), WHR: waist to hip ratio; MB: basal metabolism (kcal) for the group following the VLCKD_MED diet (orange bars) and VLCD_MED diet (green bars). Error bars depict the standard error of the mean. * depicts a significant difference, p < 0.05.

Figure 3

Percentage change in the blood chemistry variables after VLCKD_MED and VLCD_MED diet. The histogram depicts the % change (post-pre diet) in the level of: GLYCEMIA, i.e., blood glucose (mg/dL); INS, i.e., insulin (µU/mL); HB_GLIC, i.e., glycosylated hemoglobin (%); HOMA index; PEP_C, i.e., C-peptide (ng/mL); COL_TOT, i.e., total cholesterol (mg/dL); COL_LDL cholesterol (mg/dL); COL_HDL cholesterol (mg/dL) TRIG, i.e., triglyceridemia (mg/dL); GPT glutamic pyruvic transaminase (U/L), GOT, i.e., glutamic oxaloacetic transaminase (U/L); GGT, i.e., gamma-glutamyl transferase (U/L) CREAT creatinine (mg/dL) for the group following the VLCKD_MED diet (orange bars) and VLCD_MED diet (green bars). Error bars depict the standard error of the mean. * depicts a significant difference, p < 0.05.