Background: Diabetes mellitus is a global public health problem. The purposes of this study were: development of healthy eating habits, excellent glycemic control, maintenance ideal body weight, smoking cessation, regular physical exercise, prevention of complications.Methods: A sample of 100 diabetic patients (57% males and 43% females, aged 39-89 years old) was monitored in the Hospital of Tripolis. Patients completed a questionnaire about their eating habits. Body weight, height, waist circumference, body mass index (BMI) calculation and glycosylated hemoglobin were measured. Follow lifestyle intervention included dietary guidelines.Results: After the intervention significant differences were observed: increases in physical activity (58.95% from 41.0%, p-value = 0.002), duration of exercise (Q1 = 1.0 from 0.5, p-value = 0.023), consumption of breakfast (94.74% from 86.0%, p-value = 0.013 ), daily number of meals (median = 5 from 4, p-value = 0.002), average score of frequency in fats / oils / olive consumption (median = 2.8 from 2.5, p-value <0.001) average score of frequency in fruit consumption (median = 4.0 from 2.5, p-value <0.001), and decreases in weight (Q1 = 73.0 from 74.5, p-value = 0.002), BMI (median = 31.7 from 32.4, p-value = 0.002), waist circumference (median = 106 from 108, p-value <0.001), average score of frequency in grain / starchy / legumes consumption (Q1 = 2.6 from 2.8, p-value = 0.050).Conclusions: This study shows that even small interventions can have the desired results. But it needs perseverance and adaptation of programs to the specific characteristics and cultural beliefs of patients.