Table 1.
Demographic, Anthropometric, Metabolic, and ad Libitum Food Intake Measures of the Study Group
| All Subjects (n = 107) | Males (n = 62) | Females (n = 45) | Native Americans (n = 84) | Whites (n = 23) | BMI ≤29 kg/m2 (n = 32) | BMI >29 kg/m2 (n = 75) | |
|---|---|---|---|---|---|---|---|
| Age, y | 32.9 ± 8.1 | 31.9 ± 7.2 | 34.4 ± 9.1 | 32.1 ± 7.9a | 35.9 ± 8.1 | 31.4 ± 7.9 | 33.6 ± 8.1 |
| Height, cm | 168.3 ± 8.2 | 173.5 ± 5.5b | 161 ± 5.2 | 167.2 ± 8.1a | 172.2 ± 7.6 | 169.4 ± 8.1 | 167.8 ± 8.3 |
| Body weight, kg | 94.7 ± 24.4 | 96.4 ± 25.0 | 92.3 ± 23.7 | 95.4 ± 25.4 | 92.3 ± 20.6 | 71.0 ± 9.9c | 104.8 ± 21.6 |
| BMI, kg/m2 | 33.5 ± 8.3 | 32.0 ± 7.8b | 35.6 ± 8.7 | 34.1 ± 8.6 | 31.2 ± 6.9 | 24.8 ± 3.2c | 37.2 ± 6.9 |
| Body fat, % | 31.4 ± 8.4 | 26.8 ± 6.6b | 38.4 ± 5.4 | 32.1 ± 7.8 | 29.3 ± 9.8 | 24.2 ± 7.4c | 34.8 ± 6.4 |
| FM, kg | 30.2 ± 13.0 | 26.9 ± 12.0b | 35.1 ± 13 | 30.9 ± 13.2 | 28.1 ± 12.2 | 17.4 ± 5.1c | 36.2 ± 11.1 |
| FFM, kg | 62.7 ± 14.2 | 68.9 ± 13.4b | 53.6 ± 9.9 | 62.2 ± 14.7 | 64.3 ± 12.5 | 53.6 ± 9.5c | 66.8 ± 14.1 |
| Fasting glucose concentration, mg/dL | 90.4 ± 8.9 | 88.5 ± 7.8b | 93.1 ± 9.7 | 90.7 ± 9.4 | 89.6 ± 6.7 | 86.4 ± 6.0c | 92.1 ± 9.4 |
| 2-hour glucose concentration, mg/dL | 123.4 ± 33.1 | 116.5 ± 29.2b | 133 ± 35.9 | 126.0 ± 32.4 | 113.9 ± 34.5 | 111.8 ± 27.9c | 128.3 ± 34.0 |
| Glucose tolerance status | |||||||
| NGT | 76 (71%) | 49 (79%) | 27 (60%) | 58 (69%) | 18 (78%) | 25 (78%) | 51 (68%) |
| IGT | 31 (29%) | 13 (21%) | 18 (40%) | 26 (31%) | 5 (22%) | 7 (22%) | 24 (32%) |
| Respiratory chamber | |||||||
| 24-hour energy intake, kcal | 2277 ± 351 | 2422 ± 300b | 2078 ± 318 | 2271 ± 363 | 2301 ± 307 | 2017 ± 263c | 2389 ± 325 |
| 24-hour EE, kcal/d | 2452 ± 381 | 2621 ± 329b | 2218 ± 321 | 2457 ± 381 | 2434 ± 386 | 2176 ± 310c | 2570 ± 347 |
| 24-hour energy balance, kcald | −174 ± 167 | −199 ± 172 | −141 ± 153 | −186 ± 163 | −132 ± 175 | −159 ± 159 | −181 ± 170 |
| SPA, %e | 7.5 ± 2.6 | 7.8 ± 2.6 | 7.0 ± 2.6 | 7.4 ± 2.4 | 7.7 ± 3.2 | 7.3 ± 2.3 | 7.5 ± 2.8 |
| Energy cost of SPA, kcal/d·% SPAf | 63.1 ± 22.2 | 65.5 ± 22.4 | 60.0 ± 21.7 | 64.7 ± 22.4 | 57.5 ± 21.1 | 52.9 ± 18.4c | 67.5 ± 22.3 |
| SPA EE, kcal/dg | 445 ± 172 | 487 ± 177b | 388 ± 148 | 453 ± 169 | 416 ± 182 | 366 ± 136c | 479 ± 175 |
| EE0 activity, kcal/14 hh | 1267 ± 206 | 1350 ± 188b | 1152 ± 174 | 1264 ± 200 | 1280 ± 231 | 1134 ± 178c | 1324 ± 191 |
| SMR, kcal/di | 1724 ± 280 | 1819 ± 265b | 1593 ± 248 | 1723 ± 279 | 1728 ± 291 | 1517 ± 188c | 1812 ± 267 |
| AFT, kcal/14 hj | 262 ± 99 | 289 ± 108b | 223 ± 70 | 259 ± 98 | 272 ± 104 | 249 ± 100 | 267 ± 98 |
| AFT, % of energy intake | 11.6 ± 4.1 | 12.1 ± 4.6 | 10.9 ± 3.3 | 11.5 ± 4.2 | 11.7 ± 3.9 | 12.3 ± 4.4 | 11.3 ± 4.0 |
| 24-hour RQ, ratio | 0.84 ± 0.02 | 0.84 ± 0.02 | 0.84 ± 0.03 | 0.84 ± 0.02 | 0.84 ± 0.03 | 0.84 ± 0.02 | 0.84 ± 0.02 |
| Daily (fed) RQ | 0.85 ± 0.03 | 0.85 ± 0.03 | 0.85 ± 0.03 | 0.85 ± 0.03 | 0.85 ± 0.02 | 0.85 ± 0.03 | 0.85 ± 0.03 |
| Sleeping (fasting) RQ | 0.81 ± 0.04 | 0.81 ± 0.04 | 0.82 ± 0.04 | 0.81 ± 0.04 | 0.81 ± 0.04 | 0.82 ± 0.04 | 0.81 ± 0.04 |
| 24-hour carbohydrate oxidation rate, kcal/d | 1020 ± 242 | 1112 ± 242b | 896 ± 179 | 1027 ± 249 | 995 ± 218 | 916 ± 211c | 1065 ± 241 |
| 24-hour fat oxidation rate, kcal/d | 1091 ± 298 | 1150 ± 264b | 1012 ± 325 | 1104 ± 311 | 1045 ± 250 | 948 ± 258c | 1153 ± 295 |
| Computerized vending machine systemsk | |||||||
| Total ad libitum food intake, kcal/d | 4401 ± 1202 | 4931 ± 1016b | 3670 ± 1051 | 4395 ± 1185 | 4422 ± 1286 | 4351 ± 1103 | 4422 ± 1248 |
| WMEN | 2798 ± 263 | 2907 ± 243b | 2646 ± 213 | 2795 ± 270 | 2809 ± 243 | 2606 ± 167c | 2881 ± 255 |
| Total ad libitum food intake, % of WMEN | 158 ± 40 | 170 ± 34b | 142 ± 43 | 158 ± 41 | 160 ± 37 | 167 ± 40 | 155 ± 40 |
| Carbohydrate intake, g/d | 558 ± 152 | 625 ± 123b | 466 ± 140 | 560 ± 148 | 554 ± 170 | 567 ± 154 | 555 ± 152 |
| Fat intake, g/d | 189 ± 61 | 213 ± 54b | 157 ± 56 | 190 ± 63 | 185 ± 57 | 181 ± 55 | 193 ± 64 |
| Protein intake, g/d | 145 ± 45 | 158 ± 43b | 126 ± 42 | 135 ± 39a | 180 ± 49 | 144 ± 45 | 145 ± 45 |
Abbreviations: EE0 activity, EE in the inactive awake state; IGT, impaired glucose tolerance (2 h plasma glucose concentration: 140–199 mg/dL) according to American Diabetes Association diagnostic criteria (15). Values in each cell are reported as mean ± SD.
P < .05 vs whites.
P < .05 vs females.
P < .05 vs BMI greater than 29 kg/m2.
Twenty-four-hour energy balance inside the respiratory chamber was the difference between the total caloric intake of four meals (24 h energy intake) and 24-hour EE.
SPA was calculated as the average value of all the 15-minute periods between 11:00 am and 1:00 am (14 h) inside the respiratory chamber.
The energy cost of SPA was quantified by the slope of the regression line between EE and SPA between 11:00 am and 1:00 am.
The SPA-related EE was derived as the product of SPA times the slope of the regression line between EE and SPA between 11:00 am and 1:00 am.
The EE0 activity was calculated as the intercept of the regression line between EE and SPA between 11:00 am and 1:00 am.
SMR was defined as the average EE of all 15-minute nightly periods between 1:00 am and 5:00 am during which SPA was less than 1.5%.
The AFT was calculated as the difference between EE0 activity and SMR (11).
Ad libitum food intake measures are reported as the average over 3 days on the vending machines.