Background: The present study aimed to calculate the basal metabolic rate (BMR) with the Mifflin equation based on the expected body mass for normal body mass index (BMI) values in obese patients treated in spa conditions. Methods: Patients with morbid obesity (BMI > 40 kg m -2 ) and non-obese controls (BMI < 30 kg m -2 ) were recruited. In total, 104 patients with morbid obesity (mean BMI ± standard deviation, 46.9 ± 2.1 kg m -2 ) treated in spa conditions and 90 non-obese controls (mean BMI, 28 ± 1.3 kg m -2 ) were included in the present study. Results: The mean BMR calculated based on actual body mass was 2088 ± 303 kcal in patients with morbid obesity and 1424 ± 268 kcal in nonobese controls. The BMR calculated based on expected body mass for normal BMI decreased significantly in patients with morbid obesity (p < 0.01), but not in non-obese controls. Accordingly, energy expenditure and planned caloric intake was significantly lower when BMR was calculated based on expected body mass rather than actual body mass in patients with morbid obesity, but not in non-obese controls (p < 0.01). Conclusions: Expected body mass for normal BMI should be used to calculate the BMR in patients with morbid obesity.
Key points• Dietary treatment should be set individually for each patient.• A combination of balneological procedures with a low energy diet achieves the best possible results for the conservative treatment of obesity. • In the present study, using body mass for basal metabolic rate (BMR) calculation helped with the planning of a low-calorie diet. • The results showed that, when actual body mass was used to calculate the BMR with the Mifflin equation, the average daily caloric requirement was 2715 kcal.