Functional relationships between energy expenditure, body composition and eating behaviour in Roux-en-Y Gastric Bypass patients pre- and post-surgery.

Supervisors:
Dr Ruth Price
Professor Barbara Livingstone

Project Description
After Roux-en-Y gastric bypass (RYGB) patients’ appetite, energy intake, body weight, and glycemia typically decrease, and this is maintained long-term. Despite better understanding of the inhibitory control of appetite via episodic (short term) and tonic (longer term) signalling following RYGB, the excitatory drive to eat that characterises current theories of appetite control remains poorly understood. While a constant, recurring drive to eat arising from the demand for energy appears logical, the issue of whether energy expenditure influences energy intake is not yet resolved. Unlike Fat Mass (FM), in which well-established signalling pathways exist between adipose tissue and the central nervous system, the role of Fat Free Mass (FFM) in the control of appetite following RYGB has received little attention. While limited evidence suggests that FFM acts as an orexigenic signal, the functional relationships between energy expenditure, body composition and eating behaviour before and following RYGB have never been examined. Consequently, the precise role that aspects of body composition (e.g. FFM), energy expenditure [(e.g. basal metabolic rate (BMR)] or substrate oxidation play as drivers of subjective appetite or food intake in RYGB patients is unresolved.
Project aim: to assess the functional relationships between energy expenditure, body composition (as a main determinant of BMR) and eating behaviour in RYGB patients pre- and up to 2 years post-surgery.
To test this aim, morbidly obese adult patients eligible for bariatric surgery (n=32) and normal weight controls (n=32) will be recruited. All subjects will be assessed for changes in food selection and energy intake (directly assessed), basal energy requirements (indirect calorimetry), food preferences, gut hormone response and body composition (FM and FFM, dual-energy X-ray absorptiometry)) 1 mo. presurgery and 3,12, and 24 mo. postsurgery, with controls being time-matched. During each study visit participants will stay for two nights in the Human Intervention Studies Unit to allow measurements to be taken.

References and additional links
For more information on this project, the supervisory team and graduate studies at Ulster, please visit
http://www.science.ulster.ac.uk/gradschool/biomedical/

How to apply for this project:
http://www.ulster.ac.uk/research-and-innovation/phdresearch-degrees/how-to-apply

Closing date for Applications is 24 February 2017.

Funding Notes
The Department for the Economy (DfE) (formerly called Department for Employment and Learning (DEL))
The University has DfE research studentships available for PhD projects. These pay tuition fees and an annual maintenance award of not less than £14,553 per annum. These awards are open to holders of, or those expected to obtain, first or upper second class honours degrees and cover fees at the home rate and, for applicants with UK residence only, a maintenance allowance. Non-UK residents who hold ordinary EU residence may also apply but, if successful, will receive fees only. Applicants should indicate in the appropriate box on their University application form that they wish to apply for a DfE award. The closing date for receipt of applications will be 24 February 2017. Information on terms and conditions for DfE awards, including eligibility, can be found here: DfE Terms and Conditions for 2016/2017

Vice-Chancellor's Research Scholarships (VCRS)
A number of University funded VCRS will be available for PhD projects at Ulster. These awards are open to applicants who hold or, expect to obtain, a first or upper second class honours degree. They will cover tuition fees and a maintenance award of not less than £14,553 per annum for three years. Applications are invited from UK, European Union and overseas students. Applicants with up to one year’s current or previous registration for PhD at any institution may be considered for an award subject to the applicant providing evidence of good academic progress, formal release from all IP restrictions and ethical approval (if required). Three-year awards may be allocated to such applicants where they are taking-up a new project at Ulster. Applicants should indicate in the appropriate area on their University application form that they wish to apply for a University Studentship/VCRS award. The closing date for receipt of applications will be 24 February 2017. Information on terms and conditions for VCRS awards, including eligibility, can be found here: VCRS Terms and Conditions for 2016/2017