Effects of a high-protein diet versus calorie-restricted diet on weight loss and biochemical indicators improvement in overweight and obese patients: a retrospective study

To investigate the impact of a high-protein diet (HPD) versus a calorie-restricted diet (CRD) on weight loss and biochemical indicators improvement in overweight and obese individuals. 63 overweight or obese patients were enrolled, with 32 individuals assigned to the HPD group and 31 to the CRD group, each undergoing a 24-week intensive lifestyle intervention. Changes in key parameters, including body weight, body mass index (BMI), waist circumference, hip circumference, body fat percentage, glycosylated hemoglobin (HbA1c), blood glucose, insulin, adiponectin, free fatty acids, homeostasis model assessment of insulin resistance (HOMA-IR), and other relevant indicators were observed before and after the intervention. A total of 63 overweight/obese participants participated in this study, and the baseline characteristics were similar between the two groups. After a 24-week intervention, the HPD group showed significantly greater reductions in body weight, BMI, waist circumference, and body fat percentage (all P < 0.05), as well as a higher proportion of participants achieving clinically significant weight loss (≥ 10%) compared to the CRD group (58.1% vs. 19.4%, P = 0.006). Regarding biochemical indicators, the HPD group also demonstrated superior improvements in HbA1c, 2‑hour postprandial blood glucose, free fatty acids, and adiponectin. However, no significant differences between the groups were observed in changes in HOMA-IR, lipid profiles, and adiponectin levels. Both HPD and CRD are effective strategies for achieving weight loss, improving biomarkers of metabolic syndrome in overweight and obese patients. Notably, HPD has a superior effect on weight loss, being able to significantly improve central obesity, reduce body fat percentage, and improve glycemic control as well as adipocytokine profiles.