Changes in resting metabolic rate and body composition after bariatric surgery in two severely obese adolescent patients attending a bariatric healthy weight clinic: A clinical case report
Authors: Henes Sarah T , Wulkan Mark , Reddy Sheethal , Fuller Kristen , Stark Megan , Walsh Stephanie 
Published: November 2023

Background

The literature supports the concept that resting metabolic rate (RMR) decreases significantly after bariatric surgery and that there is a relationship between body composition changes and decline in RMR. Research also indicates that the greater the decline in RMR through weight loss, the greater the chance for weight regain. There are currently no data describing RMR changes of severely obese adolescent bariatric patients in the clinical setting.

Aim

This current clinical observation describes changes in RMR and body composition in two severely obese adolescents who were part of a healthy weight bariatric clinic and who underwent laparoscopic sleeve gastrectomy.

Methods

Patients who were eligible for bariatric surgery were recruited as part of a nine‐ month pilot study which aimed to observe changes in RMR in adolescents pre‐ and post –surgery. Institutional Review Board (IRB) approval was obtained and patients interested in the study signed an informed consent and assent for the measurement of RMR via indirect calorimetry. Eight patients signed informed consent for RMR testing; four patients were lost to clinical follow‐up. Four patients underwent pre‐surgery RMR testing, two of those patients underwent bariatric surgery and completed post‐surgery RMR testing. Patients participated in their usual clinical care. Patients arrived at the clinic approximately 30–45 minutes before their regularly scheduled clinic appointment and were fasting. Protocol for indirect calorimetry was followed.

Results

Pre‐surgery (one month before surgery) weight for Patient 1: 124.4kg, BMI 36.8; Patient 2 : 149.4kg, BMI 55.5. Both patients demonstrated a decline in RMR post‐surgery (Patient 1: 25% of baseline, 68 days post‐surgery; Patient 2: 5% of baseline, 94 days post‐surgery). Patient 1 lost 12.8% body weight with a decrease of RMR from 21.28kcal/kg body weight to 18.28kcal/kg. Patient 2 lost 14.8% body weight with change in RMR from 15.29kcal/kg body weight to 17.26 kcal/kg. Interestingly, patient 2 lost more muscle mass (14.1%) than patient 1 (9.4%) through surgery yet had less of a decline in RMR when compared to patient 1. Overall total percent body fat changes post‐surgery was quite small for both patients (Patient 1: −2.8%; Patient 2: −1.6%)

Conclusion

Currently, best‐practice guidelines are used in the nutrition management of adolescent bariatric patients; however, there is no standardization of nutrition care. Further research investigating the changes in RMR and body composition in severely obese adolescents undergoing bariatric surgery in the clinical setting and what may be the clinical implications of these changes is still needed. Tracking RMR and body composition over‐time may help guide clinical practice for individualized nutrition and exercise recommendations that could help prevent weight regain post‐surgery.

Support or Funding Information

Georgia State University, Lewis School of Nursing and Health Professions Intramural Grant Program 2013–2014