A Very Low Calorie Ketogenic Diet (VLCKD) has become well established as a diet for weight loss over the past years. This particular diet is characterized by carbohydrate of “50 g/day, 1-1.5 g of protein/kg of ideal body weight, 15-30 g of fat/day, and a daily intake of approximately 500-800 calories” (Muscogiuri, 2021). Indeed, many patients with medical conditions that require an effective weight loss and control, such as Type 2 diabetes mellitus, have sought to pursue similar nutrition interventions. However, the safety of higher protein diets, such as ketogenic diets, has often been a controversial topic for those with kidney impairments.

An observational study from Italy published in 2020, nonetheless, shed a rather neutral light on this matter. Its results suggested that the use of VLCKD does not pose an increased risk for patients with a mild impairment in kidney function.

A total of 92 patients with obesity were studied. This population comprised of 38 mild kidney disease patients and 54 controls, identified as those without known existing renal condition. In this work, a mild kidney disease (MKD) was identified as having an estimated glomerular filtration rate (eGFR) of 60-89 mL/min/1.73m2. Each group of subjects underwent VLCKD for about 3 months, and was checked for ketosis each week. THE VLCKD consisted of a total caloric intake of 450 to 800 per day, depending on the calculated ideal body weight. Various physical and biochemistry data were measured at baseline, then after the dietary intervention.

The results showed that patients largely benefited from VLCKD. There was a statistically significant reduction in BMI and body weight. Blood pressure, glucose metabolism, and lipid metabolism also showed overall significant improvement with lower fasting glycaemia, HbA1c level, as well as lower total cholesterol and triglyceride levels. Most pertinent to the study, the evaluation of kidney function also proved to have no significant alteration before and after the study, and no development of kidney stones or gallbladder diseases were reported by the patients. Based on the finding that VLCKD did not differentially affect the kidney function of the two groups studied, the authors concluded that it may be a safe option of diet for those with MKD.

Bear in mind, that this study does not suggest the same findings for patients with more severe cases of chronic kidney disease (eGFR <60). It must also be taken into consideration that VLCKD enforced in this study carefully followed a detailed protocol (New Penta, Cuneo, Italy), consisting of 5 phases and micronutrient supplementation. Therefore, this dietary intervention should be done under medical supervision and monitored for accurate protein consumption.