The Effects of Low-Carbohydrate Diet and Protein-rich Mixed Diet on Insulin Sensitivity, Basal Metabolic Rate and Metabolic Parameters in Obese Patients

Abstract

Objective: Various diet plans with varying ratios of carbohydrates, proteins, and fat ensure weight loss in obesity. The primary aim of our study was to evaluate the effects of weight loss on metabolic parameters, and the secondary aim was to compare the successes of various weight loss regimens in maintaining weight loss. Material and Methods: A team of doctors comprising a dietary consultant and a psychologist developed a program that was followed throughout our study. Twenty-two patients were included in our study. Based on their preference, they were classified into two groups: low carbohydrate diet (Atkins) group and protein-rich mixed diet group. Results: The mean age of the patients was 52.4 +/- 3 years, and the mean body mass index (BMI) was 36.1 +/- 1.2 kg/m(2). Five patients followed the Atkins diet, whereas 17 followed the protein-rich mixed diet. Compared with the baseline values, in the 3rd, 6th, and 12th months, body weight (BW), BMI, and waist circumference decreased significantly (p<0.001) in all the patients. Basal metabolic rate decreased in the third and sixth months but increased in the 12th. Fasting blood glucose, fasting insulin, HbA1c, 120-minute blood glucose level in oral glucose tolerance test, total cholesterol, low-density lipoprotein, free fatty acids, and uric acid did not change significantly (p>0.05). In the Atkins group, BMI decreased significantly in the 6th month (p=0.03) but increased in the 12th month (p=0.29). In the protein-rich mixed diet group, BMI (basal 35.1 +/- 1.5 kg/m(2)) decreased significantly (32.8 +/- 1.5, p<0.001) in the 6th month, and continued to decrease in the twelfth (31.5 +/- 1.2, p=0.007). Conclusion: In obesity, approximately 10% weight loss can change metabolic parameters moderately. The Atkins and protein-rich mixed diets caused similar weight loss ratios in the first six months, but a protein-rich mixed diet was more successful in terms of long-term sustainability and maintenance of weight loss.