Effects of dietary restraint vs exercise during weight maintenance in obese men

To investigate the effect of dietary restraint with or without exercise during weight maintenance after energy restriction.

In total, 40 obese male subjects (mean BMI 32.3 kg/m(2); mean age 39 y) were recruited and randomly divided into a diet (D; n=20) and a diet plus exercise (DE; n=20) group. Both groups participated in an energy restriction programme (ER), which was followed by a weight maintenance phase (WM). Subjects in the DE also participated in an exercise programme. Body mass (BM) and the scores on the three factor eating questionnaire (TFEQ) were measured before and after the ER and after WM.

No significant differences between both groups were found. All data taken together showed that BM loss during ER was explained by initial BM (r(2)=0.3, P<0.0005) and inversely by initial cognitive restraint (F1) (r(2)=0.4, P<0.0005) in a stepwise regression. BM regain during WM was explained by BM loss (r(2)=0.5, P<0.001) and by increase in F1 during ER (r(2)=0.6, P<0.001), while the exercise intervention did not contribute further to the explained variation. Subjects with a relatively high diet frequency prior to the study had relatively significant higher initial F1 scores (P<0.05). During ER, increase in F1 was associated with decrease in general hunger (F3).

Successful BM loss was associated with higher initial BM and lower initial F1. Successful WM was explained by BM loss and increase in F1 during ER, irrespective of possible exercise training effects. Successful WM was reduced when F1 scores reach their limit, due to diet-frequency.