Table 2.
Characteristics of the participants (early group vs. late group).
| Early Group (n = 47, Men: 25/Women: 22) | Late Group (n = 50, Men: 26/Women: 24) | Early Group vs. Late Group | ||||||
|---|---|---|---|---|---|---|---|---|
| Pre | Post | |||||||
| Pre | Post | ES | Pre | Post | ES | ES | ES | |
| Start of eating window (h:mm) | 6:48 ± 0:22 | 7:00 ± 0:30 * | 0.429 | 8:09 ± 1:05 †† | 8:19 ± 1:27 †† | 0.127 | 1.649 | 1.214 |
| Age (years) | 48.8 ± 6.6 | - | - | 45.8 ± 9.7 | - | - | 0.362 | - |
| Height (cm) | 165.4 ± 7.1 | - | - | 165.5 ± 8.7 | - | - | 0.013 | - |
| Body weight (kg) | 69.3 ± 12.1 | 66.7 ± 11.6 ** | 0.219 | 70.6 ± 13.7 | 68.9 ± 13.8 ** | 0.124 | 0.101 | 0.173 |
| BMI (kg/m2) | 25.2 ± 3.6 | 24.3 ± 3.4 ** | 0.257 | 25.6 ± 3.8 | 25.0 ± 4.0 ** | 0.154 | 0.108 | 0.189 |
| Body weight change (kg) | - | −2.6 ± 2.0 | - | - | −1.6 ± 1.9 † | - | - | 0.513 |
| Body weight change (%) | - | −3.7 ± 2.7 | - | - | −2.4 ± 2.6 † | - | - | 0.490 |
| Meal and sleep timing | ||||||||
| Wake time (h:mm) | 5:54 ± 0:33 | 6:05 ± 0:36 ** | 0.306 | 6:40 ± 0:42 †† | 6:46 ± 0:50 †† | 0.124 | 1.212 | 0.937 |
| Bedtime (h:mm) | 23:17 ± 0:55 | 23:15 ± 0:56 | 0.030 | 23:49 ± 1:00 † | 23:57 ± 0:55 †† | 0.135 | 0.549 | 0.744 |
| Sleep duration (min) | 396 ± 50 | 409 ± 49 * | 0.263 | 410 ± 50 | 408 ± 43 | 0.053 | 0.281 | 0.031 |
| Midpoint of sleep (h:mm) | 26:35 ± 0:38 | 26:40 ± 0:40 | 0.121 | 27:15 ± 0:46 †† | 27:22 ± 0:48 * †† | 0.143 | 0.919 | 0.927 |
| End of eating window (h:mm) | 19:27 ± 1:14 | 19:22 ± 1:00 | 0.075 | 19:48 ± 1:05 | 19:37 ± 1:05 * | 0.168 | 0.306 | 0.247 |
| Midpoint of eating window (h:mm) | 13:23 ± 0:50 | 13:11 ± 0:36 * | 0.276 | 13:47 ± 0:55 † | 13:59 ± 1:01 †† | 0.194 | 0.467 | 0.944 |
| Time elapsed between sleep offset and start of eating window (min) | 57 ± 25 | 56 ± 26 | 0.039 | 91 ± 62 † | 93 ± 78 † | 0.028 | 0.719 | 0.636 |
| Time elapsed between end of eating window and sleep onset (min) | 231 ± 71 | 231 ± 61 | 0.000 | 240 ± 59 | 259 ± 60 * † | 0.319 | 0.138 | 0.463 |
| Fasting duration (min) | 681 ± 65 | 696 ± 60* | 0.240 | 741 ± 86 †† | 759 ± 92 * †† | 0.202 | 0.787 | 0.811 |
| Dietary intake | ||||||||
| Total energy intake (kcal/day) | 1818 ± 542 | 1622 ± 390 * | 0.415 | 1977 ± 586 | 1834 ± 654 * | 0.230 | 0.282 | 0.394 |
| Total energy intake change (kcal/day) | - | −196 ± 389 | - | - | −143 ± 489 | - | - | 0.120 |
| Protein (%) | 15.4 ± 2.4 | 16.1 ± 3.3 | 0.243 | 14.9 ± 2.9 | 15.9 ± 3.0 * | 0.339 | 0.188 | 0.063 |
| Fat (%) | 28.2 ± 5.4 | 28.0 ± 6.2 | 0.034 | 28.0 ± 5.4 | 30.2 ± 5.6 * | 0.400 | 0.037 | 0.372 |
| Carbohydrate (%) | 50.5 ± 7.6 | 49.5 ± 8.5 | 0.124 | 50.5 ± 7.1 | 47.6 ± 6.8 * | 0.417 | 0.000 | 0.128 |
| Physical activity | ||||||||
| Wearing time (min/day) | 987 ± 105 | 955 ± 112 * | 0.295 | 903 ± 88 †† | 882 ± 98 * † | 0.225 | 0.867 | 0.200 |
| Step counts (steps/day) | 7607 ± 2749 | 8233 ± 2873 | 0.132 | 7658 ± 3337 | 7541 ± 3536 | 0.032 | 0.000 | 0.084 |
| ≤1.5 METs (min/day) | 603 ± 116 | 579 ± 101 | 0.007 | 578 ± 91 † | 570 ± 88 † | 0.063 | 0.279 | 0.291 |
| 1.6–2.9 METs (min/day) | 324 ± 73 | 313 ± 69 | 0.032 | 269 ± 61 † | 257 ± 69 † | 0.045 | 0.281 | 0.261 |
| 3.0 METs ≤ (min/day) | 59 ± 24 | 62 ± 23 | 0.095 | 56 ± 25 | 54 ± 26 | 0.045 | 0.045 | 0.115 |
| ≤1.5 METs (%) | 60.8 ± 8.2 | 60.4 ± 7.2 | 0.052 | 63.7 ± 6.4 | 64.4 ± 7.1 † | 0.104 | 0.394 | 0.559 |
| 1.6–2.9 METs (%) | 33.1 ± 7.3 | 33.0 ± 6.4 | 0.015 | 29.9 ± 6.3 † | 29.3 ± 7.1 † | 0.089 | 0.469 | 1.248 |
| 3.0 METs ≤ (%) | 6.1 ± 2.5 | 6.6 ± 2.4 | 0.204 | 6.4 ± 2.9 | 6.3 ± 3.1 | 0.033 | 0.111 | 0.108 |
| Step counts (steps/h wear time) | 467 ± 173 | 520 ± 188 * | 0.293 | 515 ± 232 | 520 ± 250 | 0.021 | 0.235 | 0.000 |
| ≤1.5 METs (min/h wear time) | 36.6 ± 4.9 | 36.4 ± 4.4 | 0.043 | 38.3 ± 3.9 | 38.8 ± 4.3 † | 0.122 | 0.384 | 0.552 |
| 1.6–2.9 METs (min/h wear time) | 19.8 ± 4.4 | 19.7 ± 3.9 | 0.024 | 17.9 ± 3.8 † | 17.4 ± 4.2 † | 0.125 | 0.462 | 0.568 |
| 3.0 METs ≤ (min/h wear time) | 3.6 ± 1.5 | 3.9 ± 1.4 | 0.207 | 3.8 ± 1.7 | 3.7 ± 1.8 | 0.057 | 0.125 | 0.124 |
Mean ± SD. * p < 0.05, ** p < 0.001 (pre vs. post). † p < 0.05, †† p < 0.001 (early group vs. late group). Letters in parentheses indicate units. ES indicates the effect size. Bold face indicates statistical differences with p < 0.05. A paired t-test was used for pre- vs. post-intervention comparison, and a non-paired t-test was used for comparison of the early group vs. the late group. For the results of physical activity time (min/day), an analysis of covariance adjusted for wearing time was used in comparing physical activity. BMI, Body mass index; BDHQ, Brief-type Self-administered Diet History Questionnaire; METs, metabolic equivalents; h, hour.