Effect of a Low-Carbohydrate Diet on Body Weight and Metabolic Parameters in Adults with Obesity—A Prospective Cohort Study

Introduction and Objective: Obesity is a major public health concern worldwide, contributing to metabolic disorders. Dietary interventions, particularly the low-carbohydrate diet (LCD), have been suggested as an effective strategy for weight management and metabolic improvement. This study aimed to assess the impact of a 3-month LCD program on body weight, body composition, and metabolic parameters in adults with obesity. Methods: Thirty-eight adults with obesity were recruited from the Obesity and Nutrition Clinics at King Khalid University Hospital, Riyadh, Saudi Arabia. Participants followed an LCD (60-110 g/day) for 3 months, with weekly compliance checks. Anthropometric measurements and body composition assessments were performed at baseline and at the endpoint. Metabolic parameters, including liver and renal function, HbA1c, fasting glucose, HOMA-IR, and lipid profile were assessed at the two time points. Changes were analyzed using paired-sample t-tests and Wilcoxon signed-rank tests via IBM SPSS®. Results: Thirty participants (18-50 years) completed the study. Overall, significant reductions were observed in weight (-4.96 kg, p<0.001), BMI (-2.3 kg/m2, p<0.001), waist circumference (-4.1 cm, p<0.001), hip circumference (-4.1 cm, p<0.001), fat mass (-3.7 kg, p<0.001), fat percentage (-1.4%, p<0.001), GGT (-2.3 U/L, p=0.034), triglycerides (-0.114 mmol/L, p=0.033), and HbA1c (-0.11%, p<0.001). Those achieving ≥5% weight loss (n=15) also showed significant decreases in HOMA-IR (-1.1, p=0.015). Conclusion: A 3-month LCD effectively promoted weight loss in adults with obesity, with greater metabolic benefits observed among those achieving ≥5% weight loss. The variability in individual responses to the LCD highlights the need for further research to better understand these differences and support a precision dietary approach. Disclosure: N.A. Alfadda: None. G. Aljuraiban: None. O.Z. Alzeer: None. A.A. Alfadda: Consultant; Eli Lilly and Company. Other Relationship; Novo Nordisk. Consultant; Novo Nordisk. Research Support; Ministry of Education, Saudi Arabia, King Saud University, Saudi Arabia, King Abdulaziz City for Science and Technology, Saudi Arabia, Hevolution Foundation, Saudi Arabia, Dallah Hospital, Saudi Arabia. Other Relationship; Eli Lilly and Company, Novo Nordisk.