Predictors of weight loss in patients with obesity treated with a Very Low-Calorie Ketogenic Diet

Ilaria Ernesti; Francesco Baratta; Mikiko Watanabe; Renata Risi; Elisabetta Camajani; Agnese Persichetti; Dario Tuccinardi; Stefania Mariani; Carla Lubrano; Alfredo Genco; Giovanni Spera; Lucio Gnessi; Sabrina Basciani

doi:10.3389/fnut.2023.1058364

Predictors of weight loss in patients with obesity treated with a Very Low-Calorie Ketogenic Diet

Front Nutr. 2023 Jan 25:10:1058364. doi: 10.3389/fnut.2023.1058364. eCollection 2023.

Affiliations

¹ Surgical Endoscopy Unit, Department of Surgical Sciences, Sapienza University of Rome, Rome, Italy.
² Department of Clinical Internal, Anesthesiological and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy.
³ Section of Medical Pathophysiology, Food Science and Endocrinology, Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.
⁴ Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Open University, Rome, Italy.
⁵ Department of Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Rome, Italy.

Abstract

Introduction: The Very Low-Calorie Ketogenic Diet (VLCKD) has emerged as a safe and effective intervention for the management of metabolic disease. Studies examining weight loss predictors are scarce and none has investigated such factors upon VLCKD treatment. Among the molecules involved in energy homeostasis and, more specifically, in metabolic changes induced by ketogenic diets, Fibroblast Growth Factor 21 (FGF21) is a hepatokine with physiology that is still unclear.

Methods: We evaluated the impact of a VLCKD on weight loss and metabolic parameters and assessed weight loss predictors, including FGF21. VLCKD is a severely restricted diet (<800 Kcal/die), characterized by a very low carbohydrate intake (<50 g/day), 1.2-1.5 g protein/kg of ideal body weight and 15-30 g of fat/day. We treated 34 patients with obesity with a VLCKD for 45 days. Anthropometric parameters, body composition, and blood and urine chemistry were measured before and after treatment.

Results: We found a significant improvement in body weight and composition and most metabolic parameters. Circulating FGF21 decreased significantly after the VLCKD [194.0 (137.6-284.6) to 167.8 (90.9-281.5) p < 0.001] and greater weight loss was predicted by lower baseline FGF21 (Beta = -0.410; p = 0.012), male sex (Beta = 0.472; p = 0.011), and central obesity (Beta = 0.481; p = 0.005).

Discussion: VLCKD is a safe and effective treatment for obesity and obesity related metabolic derangements. Men with central obesity and lower circulating FGF21 may benefit more than others in terms of weight loss obtained following this diet. Further studies investigating whether this is specific to this diet or to any caloric restriction are warranted.

Keywords: body composition; fibroblast growth factor 21; insulin resistance; low carbohydrate diet (LCD); protein sparing modified fasting; very low energy diet.

Grants and funding

Financial support and meal replacements were kindly provided by New Penta s.r.l. Grant support from PRIN 2017 Prot.2017L8Z2EM/and PRIN 2020 Prot. 2020NCKXBR, Italian Ministry of Education, Universities and Research.