Abstract
BackgroundReductions in physical activity (PA) are common throughout young adulthood and low PA is associated with weight gain. The SNAP Trial previously reported that two self-regulation approaches to weight gain prevention reduced weight gain over a 2-year period in 18–35 year olds. Presented here are secondary analyses examining changes in PA and the relationship between PA and weight change over 2 years.Methods599 young adults (age: 27.4 ± 4.4 yrs.; BMI: 25.4 ± 2.6 kg/m2) were randomly assigned to 1 of 3 treatment arms: Small Changes (reduce calorie intake by 100 kcals/day & add 2000 steps/day), Large Changes (lose 2.3–4.5 kg initially & increase PA to ≥250 min/wk), or Self-guided (control condition). Small and Large Changes received 10, face-to-face group sessions (months 1–4), and two 4-week refresher courses each subsequent year. Body weight and PA were objectively-measured at baseline, 4 months, 1 and 2 years. Daily steps and bout-related moderate-to-vigorous intensity PA (MVPA: ≥3 METs, ≥10-min bouts) was calculated.ResultsChanges in bout-related MVPA and daily steps did not differ among treatment groups over the 2-year period (p’s > 0.16). Collapsed across groups, participants gaining >1 lb. (n = 187; 39.6%) had smaller changes in bout-related MVPA at 4 months, 1 and 2 years relative to those maintaining or losing weight (≤1 lb. weight gain; n = 282, 60.4%, p’s < 0.05). Averaged across time points, this difference equated to 47.8 min/week. Those gaining and not gaining >1 lb. did not differ on daily steps (p’s > 0.10). Among participants engaging in ≥250 min/wk. of MVPA at 2 years (n = 181), 30% gained >1 lb. from baseline to 2 years, which was not different from those engaging in 150–250 min/wk. (n = 87; 36%; p = 0.40), but this percentage was significantly lower when compared to those engaging in <150 min/wk. (n = 176; 49%; p < 0.001).ConclusionsOn average, PA differences were not observed between young adults assigned to small or large changes self-regulation interventions to prevent weight gain. Regardless of group assignment, higher levels of MVPA were associated with better weight gain prevention over 2 years. Our data suggest that achieving >150 min/week of MVPA is needed for weight gain prevention and that increasing MVPA, rather than steps, should be targeted.Trial registrationwww.clinicaltrials.gov (NCT01183689). Registered Aug 13, 2010.
Highlights
Reductions in physical activity (PA) are common throughout young adulthood and low PA is associated with weight gain
Participants with weight data and those meeting the minimal armband wear time threshold at each time point were included in the analyses and retention rates did not differ by treatment arm at any time point (p’s > 0.08, see Appendix 1 Consort diagram and Additional file 1: checklist)
Study participants were highly active at baseline with 60.2% achieving ≥150 min/ week of bout-related moderate-to-vigorous intensity PA (MVPA), 40.8% achieving ≥250 min/ week of bout-related MVPA, and 28.4% averaging the national recommendation for daily steps (≥10,000 steps/ day)
Summary
Reductions in physical activity (PA) are common throughout young adulthood and low PA is associated with weight gain. Previous literature demonstrates that young adults (ages 18–35) experience a faster rate of weight gain than other age groups, gaining an average of 1 lb./year [1, 2] This is of concern given that rapid weight gain among young adults has been linked to elevated cardiovascular disease risk factors and other adverse health outcomes [3]. Young adulthood is marked by reductions in physical activity (PA), which typically begin during adolescence and continue throughout young adulthood This is a highly transitional period, often characterized by significant life events (e.g., starting a new job, getting married, or having children); it is possible that these major life transitions may be a contributing factor to the observed decrease in PA [6, 7] and subsequent weight gain [8, 9]. Given that weight gain is most common in young adults, it is unclear whether this magnitude of PA is sufficient for preventing weight gain in this age group
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
