Table 4. Change in Physical Activity and Diet for Postpartum Participants in the Standard Care vs Intervention Groupsa,b.
| Standard Care Groupc | Intervention Groupc | Between-Group Differences, Mean (95% CI) |
P Value | Model P Valuesd | |||||
|---|---|---|---|---|---|---|---|---|---|
| Least-Squares Mean (95% CI)h | No. of Participants | Least-Squares Mean (95% CI)h | No. of Participants | Groupe | Timef | Group × Timeg | |||
| Sedentary, min/d | .88 | <.001 | .46 | ||||||
| Baseline | 319 (288 to 350) | 160 | 298 (264 to 332) | 136 | |||||
| Change from baseline to 6 mo | −49 (−84 to −14) | 103 | −27 (−65 to 12) | 92 | 23 (−30 to 75) | .40 | |||
| Change from baseline to 12 mo | −75 (−112 to −37) | 85 | −42 (−83 to 0) | 70 | 33 (−24 to 90) | .24 | |||
| Light-intensity physical activity (1.5 to <3.0 METs), min/d | .47 | <.001 | .71 | ||||||
| Baseline | 261 (229 to 294) | 160 | 266 (231 to 302) | 136 | |||||
| Change from baseline to 6 mo | −66 (−98 to −34) | 103 | −46 (−81 to −11) | 92 | 20 (−28 to 68) | .41 | |||
| Change from baseline to 12 mo | −77 (−111 to −42) | 85 | −70 (−108 to −32) | 70 | 7 (−45 to 59) | .80 | |||
| Total moderate to vigorous physical activity (≥3 METs), min/d | .61 | .03 | .76 | ||||||
| Baseline | 37.7 (30.7 to 44.6) | 160 | 38.9 (31.3 to 46.4) | 136 | |||||
| Change from baseline to 6 mo | −5.6 (−12.6 to 1.3) | 103 | −2.3 (−9.9 to 5.2) | 92 | 3.3 (−7.1 to 13.7) | .53 | |||
| Change from baseline to 12 mo | −7.2 (−14.6 to 0.3) | 85 | −7.8 (−16.1 to 0.4) | 70 | −0.7 (−42.0 to 10.6) | .91 | |||
| Total calories, kcal/dh | .02 | <.001 | .06 | ||||||
| Baseline | 1785 (1691 to 1879) | 191 | 1762 (1661 to 1863) | 170 | |||||
| Change from baseline to 6 mo | −123 (−232 to −13) | 154 | −299 (−418 to −181) | 129 | −176 (−340 to −12) | .03 | |||
| Change from baseline to 12 mo | −144 (−257 to −32) | 143 | −298 (−423 to −174) | 111 | −154 (−325 to 17) | .07 | |||
| Percentage of calories from carbohydrates | .01 | .71 | .46 | ||||||
| Baseline | 48.4 (46.7 to 50.1) | 192 | 50.0 (48.1 to 51.9) | 170 | |||||
| Change from baseline to 6 mo | −0.9 (−2.8 to 1.0) | 154 | 0.3 (−1.9 to 2.4) | 129 | 1.1 (−4.1 to 1.8) | .44 | |||
| Change from baseline to 12 mo | −1.5 (−3.5 to 0.5) | 143 | 0.3 (−1.9 to 2.5) | 111 | 1.8 (−4.9 to −1.2) | .23 | |||
| Percentage of calories from protein | .88 | .53 | .49 | ||||||
| Baseline | 17.1 (16.2 to 18.1) | 192 | 17.2 (16.2 to 18.1) | 170 | |||||
| Change from baseline to 6 mo | 0.0 (−0.9 to 0.93) | 154 | 0.5 (−0.5 to 1.6) | 129 | −0.5 (−1.9 to 0.9) | .44 | |||
| Change from baseline to 12 mo | 0.6 (−0.4 to 1.51) | 143 | 0.2 (−0.9 to 1.3) | 111 | 0.4 (−1.0 to 1.8) | .63 | |||
| Percentage of calories from fat | .02 | .91 | .52 | ||||||
| Baseline | 35.2 (33.7 to 36.6) | 192 | 33.4 (31.8 to 34.9) | 170 | |||||
| Change from baseline to 6 mo | 0.8 (−0.74 to 2.3) | 154 | −0.5 (−2.1 to 1.2) | 129 | 1.2 (−1.1 to 3.5) | .27 | |||
| Change from baseline to 12 mo | 0.4 (−1.2 to 1.9) | 143 | 0.2 (−1.6 to 1.9) | 111 | 0.2 (−2.2 to 2.6) | .86 | |||
Abbreviation: MET, metabolic equivalent.
Physical activity was based on objective assessment for a 1-week period; 97.5% of participants (361 of 370) completed this at baseline, 71.0% (263 of 370) at 6 months, and 60.5% (224 of 370) at 12 months. Of these, proportions with valid data were 296 of 361 participants (82%) at baseline; 195 of 263 participants (74%) at 6 months and 155 of 224 participants (69%) at 12 months. The analysis excluded 28 women (16 from the standard care group and 12 from the intervention group) due to suboptimal actigraph wear time at all 3 assessments (ie, <8 h and <2 d) and 3 from the standard care group due to missing covariates, resulting in 339 included in the analytic sample. Participants who completed vs did not complete the actigraph measures at 12 months did not significantly differ in group assignment, age, ethnicity, weight status, weeks post partum, income, or employment at study entry.
Diet was based on data from the Automated Self-Administered 24-Hour dietary assessment tool; 99.2% of participants (367 of 370) completed this assessment at baseline, 78.1% (289 of 370) at 6 months, and 69.7% (258 of 370) at 12 months. The analysis excluded 3 women from the standard care group due to missing covariates, resulting in 367 included in the analytic sample. Participants who completed vs did not complete the diet measure at 12 months did not significantly differ in group assignment, age, ethnicity, weight status, weeks post partum, income, or employment at study entry.
The standard care group received the standard Special Supplemental Nutrition Program for Women, Infants, and Children (WIC program). The intervention group received the standard WIC program plus a 12-month primarily internet-based weight loss program adapted from prior programs.
Mixed-effects models with covariates (ethnicity, weeks post partum at study entry, weight status, lactation, and age).
Indicates group differences in the outcome measure overall, regardless of time.
Indicates outcome changes over time, regardless of group.
Indicates group differences in the outcome over time.
Presented as least-squares mean (95% CI), which is the model-estimated response under each treatment condition evaluated for covariates (ie, ethnicity, weight status, weeks post partum at study entry, lactation, and age) at their mean levels.