Abstract
BACKGROUND: Physical activity (PA) interventions for the promotion of weight-management may benefit from increased choice and flexibility to overcome commonly-perceived barriers to PA. The aim of this study was to investigate the effects of a novel "points-based" approach to PA on body composition in inactive women, who are overweight or obese. METHODS: Seventy-six overweight or obese, inactive women were randomly allocated to one of three conditions: 'Points-based' PA (PBPA; 30 "PA points"•week(- 1)), Structured exercise (StructEx; 150 min moderate-intensity exercise•week(- 1)) or control (CONT; continue habitual inactive lifestyle) for a 24-week intervention. PA points for activities were adapted from MET values, and 30 points was equivalent to 150 min of brisk walking. Measures of body composition (dual-energy x-ray absorptiometry) and anthropometry were obtained at weeks 0, 4, 12 and 24. Self-report activities were recorded weekly, with objective measures of PA (tri-axial accelerometry) and self-report measures of food intake obtained at weeks 0 and 24. RESULTS: Fifty-eight women completed the study and provided data for primary outcomes. Of these, n = 41 and n = 19 provided data for food intake and objectively assessed PA. Mixed-design ANOVAs demonstrated that those in PBPA achieved a significant weight-loss at 24 weeks of - 3.3 ± 5.9 kg (- 3.4 ± 7.1%, p = 0.004). Waist circumference was reduced in PBPA at 24 weeks (- 2.8 ± 4.6 cm), compared with CONT (+ 2.1 ± 6.6 cm, p = 0.024). There was a trend for greater reductions in fat mass for those in PBPA vs. CONT (- 2.3 ± 4.6 kg vs. + 0.1 ± 2.0 kg, p = 0.075). Android fat was reduced in PBPA at both 12 weeks (- 6.1 ± 12.6%, p = 0.005) and 24 weeks (- 10.1 ± 18.4%, p = 0.005), while there was a trend for greater reductions in visceral adipose tissue in PBPA (- 5.8 ± 26.0%) vs. CONT at 24 weeks (+ 7.8 ± 18.3%, p = 0.053). Body composition, body weight and waist circumference were unchanged in StructEx. There were trends for increases in light-activity and reductions in sedentary time in PBPA. There was a trend for a reduction in daily energy intake of - 445 ± 564 kcal (p = 0.074), and a significant reduction in daily fat intake (p = 0.042) in PBPA. CONCLUSION: A "points-based" approach to physical activity appears to be an effective strategy for inducing modest reductions in body weight and body fat in inactive women with overweight and obesity. TRIAL REGISTRATION: NCT02020239 . Registered 12th December 2013.