Table 1.
Frequency distributions (mean ± SD or N [%]) of participants' characteristics according to self-reported habitual energy expenditure.
| Habitual energy expenditure (MET-hours/week)1 |
||||||
|---|---|---|---|---|---|---|
| Characteristic | Low n=25 |
Moderate n=92 |
High n=142 |
|||
| Age (years) | 26.0±6.8 | 27.1±7.5 | 27.6±8.9 | |||
| <20 | 3 | 12.0 | 8 | 8.7 | 28 | 19.7 |
| 20-29 | 17 | 68.0 | 56 | 60.9 | 63 | 44.4 |
| 30-39 | 3 | 12.0 | 20 | 21.7 | 28 | 19.7 |
| ≥40 | 2 | 8.0 | 8 | 8.7 | 23 | 16.2 |
| Race3 | ||||||
| White | 10 | 40.0 | 51 | 55.4 | 93 | 65.5 |
| Black | 8 | 32.0 | 16 | 17.4 | 27 | 19.0 |
| Asian / Pacific Islander | 5 | 20.0 | 22 | 23.9 | 13 | 9.2 |
| Other | 2 | 8.0 | 3 | 3.3 | 9 | 6.3 |
| Education (highest grade completed) | ||||||
| High school | 1 | 4.0 | 17 | 18.5 | 15 | 10.6 |
| Post-secondary | 24 | 96.0 | 75 | 81.5 | 127 | 89.4 |
| Family income | ||||||
| <$19,999 | 5 | 20.0 | 20 | 21.7 | 30 | 21.3 |
| $20,000-39,999 | 8 | 32.0 | 27 | 29.4 | 26 | 18.3 |
| $40,000-74,999 | 6 | 24.0 | 25 | 27.2 | 41 | 28.9 |
| $75,000-99,999 | 5 | 20.0 | 14 | 15.2 | 26 | 18.3 |
| >$100,000 | 1 | 4.0 | 5 | 5.4 | 12 | 12.7 |
| Missing | 0 | 0.0 | 1 | 1.1 | 1 | 0.7 |
| Marital status | ||||||
| Married/living as married | 6 | 24.0 | 23 | 25.0 | 37 | 26.1 |
| Separated/divorced | 0 | 0.0 | 6 | 6.5 | 10 | 7.0 |
| Single | 19 | 76.0 | 63 | 68.5 | 95 | 66.9 |
| Body mass index (kg/m2) | 23.5±4.1 | 24.1±4.0 | 24.2±3.8 | |||
| <18.5 | 2 | 8.0 | 1 | 1.1 | 6 | 4.2 |
| 18.5-24.9 | 16 | 64.0 | 61 | 66.3 | 83 | 58.5 |
| 25.0-29.9 | 5 | 20.0 | 19 | 20.7 | 40 | 28.2 |
| ≥30.0 | 2 | 8.0 | 11 | 12.0 | 13 | 9.2 |
| Body fat (% of total composition) | 30.0±7.0 | 30.0±5.7 | 29.2±6.0 | |||
| Ever smoked regularly | ||||||
| Never | 21 | 84.0 | 77 | 83.7 | 113 | 79.6 |
| Past | 3 | 12.0 | 11 | 12.0 | 23 | 16.2 |
| Present | 1 | 4.0 | 4 | 4.4 | 6 | 4.2 |
| Alcohol consumption in past year | ||||||
| <12 drinks | 12 | 48.0 | 32 | 34.8 | 41 | 18.9 |
| ≥12 drinks | 13 | 52.0 | 59 | 64.1 | 100 | 70.4 |
| Missing | 0 | 0.0 | 1 | 1.1 | 1 | 0.7 |
| Hours of sleep per day3 | 7.5±0.2 | 7.6±0.1 | 7.3±0.1 | |||
| Nulliparous | 21 | 84.0 | 73 | 79.4 | 99 | 69.7 |
| Season of baseline visit | ||||||
| Winter (Dec.-Feb.) | 8 | 32.0 | 30 | 32.6 | 38 | 26.8 |
| Spring (Mar.-May) | 10 | 40.0 | 20 | 21.7 | 29 | 20.4 |
| Summer (June-Aug.) | 2 | 8.0 | 23 | 25.0 | 43 | 30.3 |
| Autumn (Sept.-Nov.) | 5 | 20.0 | 19 | 20.7 | 32 | 22.5 |
| Length of first study cycle (days) | 29.5±3.6 | 29.1±4.8 | 28.7±4.7 | |||
| Energy (kcal)2 | 1335±1022 | 1622±753 | 1677±741 | |||
| Total dietary vitamin A (IU) | 6522±6416 | 9432±8381 | 9010±6625 | |||
| A verage daily fruit & veg (servings)2 | 2.1±1.8 | 3.6±3.6 | 4.0±4.0 | |||
1
Habitual activity was classified according to IPAQ scoring guidelines (16); see methods section for details.
2
Low- versus high-category energy expenditure p-value <0.05, using chi-square for categorical variables and unpaired t-test for continuous variables.
3
Moderate- versus high-category energy expenditure p-value <0.05, using chi-square for categorical variables and unpaired t-test for continuous variables.