Physical activity and low-fat diet: is it enough to maintain weight stability in the reduced-obese individual following weight loss by drug therapy and energy restriction?
OBJECTIVE
The anthropometric and physiological effects of a physical activity (PA) and a mildly energy-restricted low-fat diet (LFD) follow-up program after a long-term dietary restriction were studied in 12 men and 8 women.


METHODS
The dietary restriction (approximately 700 kcal/day) was accompanied by a fenfluramine (60 mg/day) or placebo treatment for 15 weeks, whereas the mean duration of the PA-LFD follow-up was 18 weeks.


RESULTS
The long-term dietary restriction reduced body weight (-11.9 and -7.6 kg, p<.001), fat mass (FM) (-10.6 and -5.8 kg, p<0.01), resting metabolic rate (RMR) (-304 kcal/day, p<0.01 and -148 kcal/day, NS) in men and women, respectively. A decrease in fat-free mass (FFM) was also observed in women (-1.8 kg, p<0.05). The PA-LFD follow-up preserved weight stability at a reduced body weight and caused an additional significant decrease in FM for men (-3.4 kg, p<0.05). This part of the intervention also caused an increase in daily RMR for men (134 kcal/day, NS) to the point where this value no longer differed from the pre-energy restriction value. In contrast, RMR was further reduced in women (-200 kcal/day) to the point where it significantly differed from initial values (p<0.01). Resting seated heart rate was reduced by the PA-LFD follow-up in men leading it to differ significantly from both pre- and post-energy restriction values (-8.5 and -5.5 bpm, p<0.01).


CONCLUSIONS
In conclusion, these results suggest that a PA-LFD follow-up has the potential to permit body weight stability and may even accentuate fat loss in the reduced-obese state. Moreover, resting energy expenditure is increased under such conditions in men. These stimulating effects seem to be specific to energy metabolism since seated heart rate was either further reduced or remained stable in response to the PA-LFD follow-up.
Doucet
E
E
Physical Activity Sciences Laboratory, Laval University, Ste-Foy, Québec, Canada.
Imbeault
P
P
Alméras
N
N
Tremblay
A
A
D000328:Adult; D001067:Appetite Depressants / Q000627:therapeutic use; D015992:Body Mass Index; D002153:Calorimetry, Indirect; D015331:Cohort Studies; D018752:Diet, Fat-Restricted; D004452:Echocardiography; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D005277:Fenfluramine / Q000627:therapeutic use; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D009765:Obesity / Q000178:diet therapy* / Q000188:drug therapy; D015431:Weight Loss
D001067:Appetite Depressants; D005277:Fenfluramine