Individual variability following 12 weeks of supervised exercise: identification and characterization of compensation for exercise-induced weight loss.
OBJECTIVE
To identify and characterize the individual variability in compensation for exercise-induced changes in energy expenditure (EE).


METHODS
Twelve-week exercise intervention.


METHODS
Thirty-five overweight and obese sedentary men and women (body mass index, 31.8+/-4.1 kg m(-2); age, 39.6+/-11.0 years) were prescribed exercise five times per week for 12 weeks under supervised conditions.


METHODS
Body weight, body composition, resting metabolic rate (RMR), total daily energy intake (EI) and subjective appetite sensations were measured at weeks 0 and 12.


RESULTS
When all subjects' data were pooled, the mean reduction in body weight (3.7+/-3.6 kg) was significant (P<0.0001) and as predicted, which suggested no compensation for the increase in EE. However, further examination revealed a large individual variability in weight change (-14.7 to +1.7 kg). Subjects were identified as compensators (C) or noncompensators (NC) based on their actual weight loss (mean NC=6.3+/-3.2 kg and C=1.5+/- 2.5 kg) relative to their predicted weight loss. C and NC were characterized by their different metabolic and behavioural compensatory responses. Moderate changes in RMR occurred in C (-69.2+/-268.7 kcal day(-1)) and NC (14.2+/-242.7 kcal day(-1)). EI and average daily subjective hunger increased by 268.2+/-455.4 kcal day(-1) and 6.9+/-11.4 mm day(-1) in C, whereas EI decreased by 130+/-485 kcal day(-1) and there was no change in subjective appetite (0.4+/-9.6 mm day(-1)) in NC.


CONCLUSIONS
These results demonstrate that expressing the exercise-induced change in body weight as a group mean conceals the large inter-individual variability in body weight and compensatory responses. Individuals who experience a lower than predicted weight loss are compensating for the increase in EE.
King
N A
NA
Biopsychology Group, Institute of Psychological Sciences, University of Leeds, Leeds, UK. n.king@leeds.ac.uk
Hopkins
M
M
Caudwell
P
P
Stubbs
R J
RJ
Blundell
J E
JE
D000328:Adult; D001066:Appetite / Q000502:physiology; D001481:Basal Metabolism / Q000502:physiology; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D002149:Energy Intake; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000503:physiopathology* / Q000628:therapy; D015431:Weight Loss / Q000502:physiology*