Examining the Effects of Weight Loss on Energy Expenditure in Humans

FieldValue
dc.contributor.authorSchwartz, Alexander
dc.date.accessioned2011-11-30T19:27:32Z
dc.date.available2011-11-30T19:27:32Z
dc.date.created2011
dc.date.issued2011
dc.identifier.urihttp://hdl.handle.net/10393/20455
dc.identifier.urihttp://dx.doi.org/10.20381/ruor-5070
dc.description.abstractBeing able to effectively match energy intake to energy expenditure (EE) is an important aspect in preventing weight re-gain in the post-obese. Although it is generally agreed upon that resting EE decreases concomitantly with weight loss, there is no set standard comparing the deviations with differing weight loss protocols and additionally, controversy remains as to whether this decrease is greater than can predicted. In order to address these issues 2977 subjects were analyzed using a systematic review and the differences of both the protocol and length of various interventions in addition to sex were compared. Next, data was selected from this systematic review and 815 subjects were analyzed for weight loss-induced changes in resting EE, FM and FFM. Another subgroup of studies (n = 1450) was analyzed and compared against the Harris-Benedict prediction equation to determine whether the changes in resting EE were greater than what was expected. Finally, in order to determine which factors may be involved in regulating changes in resting EE during weight loss, a secondary analysis was performed on 28 post-menopausal women (age= 50.4 ± 2.0 yrs; BMI= 32.4 ± 5.2 kg/m²) who were submitted to a 6-month caloric restriction. Body composition (DXA), resting EE (indirect calorimetry), physical activity EE (PAEE) and total EE (TEE) (doubly-labelled water) were measured before and after the 6 month weight loss. Blood samples were collected before and after to measure leptin and peptide YY. The results indicate that there was indeed a depression in resting EE during weight loss regardless of the type of intervention utilized. Furthermore, these findings suggest that the changes could not fully be explained by changes of FM and FFM alone and that leptin may be an important contributor to the changes of resting EE during weight loss.
dc.language.isoen
dc.publisherUniversité d'Ottawa / University of Ottawa
dc.subjectenergy expenditure
dc.subjectobesity
dc.subjectadaptive thermogenesis
dc.subjectfat mass
dc.subjectfat-free mass
dc.subjectLeptin
dc.subjectpeptide YY
dc.subjectweight loss
dc.titleExamining the Effects of Weight Loss on Energy Expenditure in Humans
dc.typeThesis
dc.faculty.departmentSciences de l'activité physique / Human Kinetics
dc.contributor.supervisorDoucet, Eric
dc.embargo.termsimmediate
dc.degree.nameMSc
dc.degree.levelmasters
dc.degree.disciplineSciences de la santé / Health Sciences
thesis.degree.nameMSc
thesis.degree.levelMasters
thesis.degree.disciplineSciences de la santé / Health Sciences
uottawa.departmentSciences de l'activité physique / Human Kinetics
CollectionThèses, 2011 - // Theses, 2011 -

Files