Effects of a very low-calorie ketogenic diet on energy metabolism and inflammation in obesity management: A systematic review

Alberta Humolli; Vilma Urbancic Rovan; Venera Berisha-Muharremi

Alberta Humolli Department of Endocrinology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
Vilma Urbancic Rovan Department of Endocrinology, Diabetes and Metabolic Diseases, University Medical Centre, Ljubljana, Slovenia
Venera Berisha-Muharremi Department of Internal Medicine, Medical Faculty, University of Prishtina, Prishtina, Kosovo

Keywords: VLCKD, Very-Low-Calorie Ketogenic Diet, high-sensitivity C-reactive protein, hs-CRP, osteocalcin, inflammation, bone metabolism, obesity

Abstract

Obesity represents a long-term health issue that leads to body-wide inflammation, together with changes in metabolic operations. Bone metabolism and remodeling are indicated by osteocalcin, while high-sensitivity C-reactive protein (hs-CRP) functions as a crucial marker for inflammation. This review investigates how very low-calorie ketogenic diets affect obese patients’ hs-CRP and osteocalcin biomarker levels. Seven research articles from 2019 to 2024 were reviewed to analyze direct biomarker changes after VLCKD interventions. The research shows that VLCKD delivers substantial anti-inflammatory effects through hs-CRP level reductions between 30% and 50%. The research showed sex-related differences because men experienced a more significant reduction in hs-CRP levels at −41.42% compared to women who experienced −22.38%. The results suggest that hormonal or metabolic factors influence how individuals respond to this treatment. The research shows variable osteocalcin level changes between studies, with some trials reporting increases between 10% and 30% but other trials showing minimal changes. Research design, along with study duration and participant characteristics, might explain these inconsistent results. The anti-inflammatory effects of VLCKD appear beneficial for obese patients, but the impact on bone biomarkers remains unclear. Additional research using standardized methods across extended periods is needed to determine these effects precisely for clinical practice guidance.