Health Related Quality of Life Improvements Associated With Exercise/Diet Changes

Purpose

The SF-36 measures health-related quality of life (HRQOL) through eight domains addressing physical and mental functioning. It has been used to demonstrate changes in psychosocial functioning in weight loss trials which have primarily studied functional status in clinically obese patients. No studies have been identified in which researchers attempted to understand the impact of weight loss on physical and mental domains of HRQOL in apparently healthy, overweight sedentary populations who had initiated an exercise and diet program. Therefore, the purpose of this study was to measure changes in HRQOL using the SF-36 in young, sedentary participants who attempted to change body fat levels by initiating an exercise program and following either a higher protein diet or higher carbohydrate diet.

Methods

Participants were (N=94) randomly placed in a higher protein (25% protein, 30% fat, 45% carbohydrate [diet1]) or higher carbohydrate group (15% protein, 30% fat, 55% carbohydrate [diet 2]) with each group initiating an aerobic exercise program. The exercise program followed the guidelines suggested by US Surgeon General's Report (1996). Body composition (BC) was measured by Dual energy X-ray absorptiometry (DEXA) along with weight, while HRQOL changes were measured using the SF-36. BC, weight, and HRQOL were measured at baseline and 12-weeks.

Analysis/Results

Role-Physical scores changed significantly in Diet 1 (p=.0001) and Diet 2 (p=.026) with higher posttest-scores when compared to pretest-scores in each group. A significant time/diet interaction occurred (p=.049) with posttest-scores higher in Diet 2 when compared to Diet 1. Social functioning pretest-scores in both diets were lower than their respective posttest-scores (p=.015). ANOVA revealed no significant differences in average calories between groups (p=.88). Exercise in minutes were recorded with no significant differences between groups at the end of the study (p=.66). Diet analysis revealed that each group followed the protocol guidelines suggested for their group.

Conclusions

Only one study was discovered that assessed the effect of unsuccessful weight loss attempts on changes in HRQOL. Therefore the discovery that significant changes in BC and weight did not occur in either group suggests that changes in HRQOL may be independent of BC or weight changes and is a novel finding. Finally, in this study improvements in HRQOL were demonstrated in two subscales. These novel findings add to literature suggesting that HRQOL, at least concerning social functioning, work and other daily activities (Role-Physical) may improve by initiating an exercise program while following either a higher protein or higher carbohydrate diet.