A Prospective Pilot Study of Body Composition Assessment in Bariatric Patients

Bariatric (weight loss) surgery results in a significant fat mass loss over a long period of time, with some evidence suggesting this continues for several years after the initial surgery. Fat free mass (lean body mass) also shows an early post surgery loss which is like to slow down after six months. Bone mineral density has not been as extensively investigated, but is likely to have a small but significant loss following bariatric surgery, although no adverse health problems have been noted.

The biggest issues regarding body composition assessment in bariatric patients is that very little research has been done on the different types of surgeries such as sleeve gastrectomy and Roux-en-Y gastric bypass, also that there is an inadequacy of long-term data. Additionally, only sparse evidence exists to support the notion that a pre surgery very-low calorie diet demonstrates a change in body composition. Further research would be greatly beneficial in exploring these limitations in our knowledge.

This study will contribute to patient care, surgical education, and will promote awareness and understanding for both patients and surgeons about the expected body composition impact of bariatric surgery.

Aims:

• To characterize longitudinal body composition patterns in patients undergoing bariatric surgery

• To compare fat mass, fat-free mass and bone mineral density, before and after pre-operative very-low calorie diets, and after surgery

• To compare body composition changes between different types of bariatric surgeries