Bone loss accompanying diet-induced or exercise-induced weight loss: a randomised controlled study.
OBJECTIVE
To compare the effects of two weight loss interventions, diet or exercise, on changes in bone, fat and lean tissue.


METHODS
Prospective, long term, worksite, randomised and controlled weight-loss study using a low fat diet ad libitum or moderate aerobic exercise.


METHODS
66 overweight men (mean age 43.4 +/- 5.7 y, BMI 29.0 +/- 2.6 kg/m2).


METHODS
Body weight, lean mass, fat mass, bone mass (BMC), bone mineral density (BMD) by dual-energy X-ray absorptiometry.


RESULTS
Dieters lost 1.4% BMC (1.5% BMD) with 6.4 kg weight loss; there was no significant change in BMC (or in BMD) in exercisers (2.6 kg weight loss) or in control subjects (no weight change). Changes in BMC were correlated with fat loss with both interventions: 11.7 g BMC/kg fat loss in dieters, 11.4 g BMC change/kg fat loss in exercisers.


CONCLUSIONS
BMC loss with diet-induced weight loss reflects loss of weight and especially loss of body fat. Further study to determine whether similar BMC loss will accompany equivalent weight loss induced by exercise is needed.
Pritchard
J E
JE
Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Australia. Jan_Pritchard.Physiology@muwaye.unimelb.edu.au
Nowson
C A
CA
Wark
J D
JD
D015502:Absorptiometry, Photon; D000328:Adult; D000886:Anthropometry; D001823:Body Composition / Q000187:drug effects / Q000502:physiology; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D001862:Bone Resorption / Q000503:physiopathology*; D003131:Combined Modality Therapy; D018752:Diet, Fat-Restricted / Q000009:adverse effects* / Q000592:standards; D004038:Diet, Reducing / Q000009:adverse effects* / Q000592:standards; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology / Q000628:therapy; D011446:Prospective Studies; D015431:Weight Loss / Q000502:physiology*