Table 3.
Caffeine consumption (mean ± SE mg/day) among Navy and Marine Corps consumers (≥1 time/week) by demographic, lifestyle, and military characteristics. (p-values are from one-way analysis of variance).
| Variable | Strata | Any Caffeine | Coffee | Hot Tea | Other Tea | Cola | Other Soda | Energy Drink | Gum/Medication |
|---|---|---|---|---|---|---|---|---|---|
| Group | All (n = 1465) | 226 ± 5 | 130 ± 4 | 8 ± 1 | 18 ± 2 | 16 ± 1 | 5 ± 1 | 37 ± 2 | 11 ± 2 |
| Gender | Men (n = 1052) | 242 ± 7 | 142 ± 5 | 5 ± 1 | 21 ± 2 | 18 ± 1 | 6 ± 1 | 43 ± 2 | 9 ± 2 |
| Women (n = 413) | 183 ± 8 | 99 ± 6 | 17 ± 2 | 12 ± 2 | 11 ± 1 | 4 ± 1 | 23 ± 3 | 17 ± 3 | |
| p-value | <0.01 | <0.01 | <0.01 | 0.03 | <0.01 | 0.28 | <0.01 | 0.04 | |
| Age (years) | 18–24 (n = 340) | 203 ± 12 | 93 ± 8 | 10 ± 2 | 24 ± 5 | 12 ± 1 | 9 ± 2 | 42 ± 4 | 14 ± 3 |
| 25–29 (n = 361) | 201 ± 11 | 106 ± 7 | 8 ± 1 | 16 ± 4 | 13 ± 1 | 4 ± 1 | 41 ± 4 | 12 ± 6 | |
| 30–39 (n = 500) | 241 ± 8 | 146 ± 7 | 7 ± 1 | 17 ± 3 | 19 ± 2 | 5 ± 1 | 39 ± 3 | 9 ± 2 | |
| ≥40 (n = 263) | 261 ± 13 | 180 ± 11 | 10 ± 2 | 16 ± 3 | 19 ± 2 | 4 ± 1 | 21 ± 4 | 10 ± 3 | |
| p-value | <0.01 | <0.01 | 0.16 | 0.40 | <0.01 | 0.03 | <0.01 | 0.79 | |
| Education | Some high school/high school graduate (n = 311) | 213 ± 12 | 100 ± 9 | 9 ± 2 | 24 ± 5 | 14 ± 2 | 9 ± 2 | 46 ± 5 | 12 ± 3 |
| Some college/Associate’s degree (n = 638) | 226 ± 8 | 122 ± 6 | 8 ± 1 | 21 ± 3 | 15 ± 1 | 6 ± 1 | 43 ± 3 | 12 ± 2 | |
| Bachelor’s/Graduate degree (n = 516) | 233 ± 9 | 157 ± 7 | 9 ± 1 | 11 ± 2 | 19 ± 2 | 2 ± 1 | 24 ± 3 | 10 ± 2 | |
| p-value | 0.39 | <0.01 | 0.47 | 0.02 | 0.08 | <0.01 | <0.01 | 0.95 | |
| Marital status | Single (n = 471) | 209 ± 9 | 107 ± 7 | 12 ± 2 | 20 ± 4 | 13 ± 1 | 7 ± 1 | 37 ± 3 | 13 ± 3 |
| Married (n = 994) | 234 ± 6 | 140 ± 5 | 7 ± 1 | 17 ± 2 | 17 ± 1 | 5 ± 1 | 37 ± 3 | 10 ± 5 | |
| p-value | 0.03 | <0.01 | <0.01 | 0.41 | 0.03 | 0.16 | 0.99 | 0.57 | |
| Race/ethnicity | White (n = 966) | 249 ± 7 | 147 ± 5 | 8 ± 1 | 18 ± 2 | 19 ± 1 | 6 ± 1 | 40 ± 3 | 12 ± 3 |
| Black (n = 150) | 150 ± 14 | 69 ± 8 | 11 ± 2 | 15 ± 5 | 10 ± 2 | 5 ± 2 | 29 ± 5 | 10 ± 3 | |
| Hispanic (n = 222) | 196 ± 12 | 106 ± 7 | 7 ± 1 | 21 ± 6 | 11 ± 2 | 2 ± 1 | 36 ± 5 | 11 ± 3 | |
| Other (n = 127) | 189 ± 14 | 109 ± 12 | 14 ± 3 | 15 ± 3 | 11 ± 3 | 6 ± 2 | 27 ± 5 | 7 ± 5 | |
| p-value | <0.01 | <0.01 | 0.04 | 0.78 | <0.01 | 0.31 | 0.14 | 0.90 | |
| Body mass index (kg/m2) | <25.0 (n = 566) | 198 ± 8 | 112 ± 6 | 11 ± 1 | 17 ± 3 | 15 ± 1 | 7 ± 1 | 28 ± 3 | 7 ± 2 |
| 25.0–29.9 (n = 740) | 247 ± 8 | 143 ± 6 | 7 ± 1 | 19 ± 3 | 16 ± 1 | 4 ± 1 | 43 ± 3 | 13 ± 3 | |
| ≥30.0 (n = 146) | 230 ± 17 | 132 ± 13 | 4 ± 1 | 15 ± 3 | 19 ± 3 | 4 ± 1 | 43 ± 7 | 14 ± 4 | |
| p-value | <0.01 | <0.01 | <0.01 | 0.71 | 0.56 | 0.14 | <0.01 | 0.29 | |
| Alcohol consumption | None (n = 302) | 192 ± 12 | 93 ± 8 | 7 ± 1 | 16 ± 3 | 18 ± 2 | 7 ± 2 | 31 ± 4 | 19 ± 8 |
| <1.34 g/day (n = 278) | 208 ± 11 | 107 ± 8 | 13 ± 2 | 18 ± 4 | 15 ± 2 | 4 ± 1 | 35 ± 5 | 13 ± 3 | |
| 1.34–3.99 g/day (n = 293) | 229 ± 13 | 141 ± 11 | 5 ± 1 | 21 ± 5 | 14 ± 2 | 4 ± 2 | 36 ± 4 | 10 ± 3 | |
| 4.00–8.93 g/day (n = 296) | 237 ± 11 | 147 ± 8 | 8 ± 1 | 15 ± 3 | 15 ± 2 | 4 ± 1 | 38 ± 4 | 9 ± 3 | |
| >8.93 g/day (n = 296) | 263 ± 12 | 159 ± 9 | 9 ± 2 | 21 ± 4 | 18 ± 2 | 5 ± 1 | 47 ± 5 | 5 ± 2 | |
| p-value | <0.01 | <0.01 | <0.01 | 0.76 | 0.43 | 0.22 | 0.02 | 0.20 | |
| Aerobic exercise duration | <101 min/week (n = 361) | 225 ± 10 | 129 ± 8 | 8 ± 1 | 16 ± 3 | 19 ± 2 | 5 ± 2 | 40 ± 5 | 7 ± 2 |
| 101–180 min/week (n = 343) | 225 ± 10 | 131 ± 8 | 8 ± 2 | 18 ± 4 | 19 ± 2 | 6 ± 1 | 34 ± 4 | 9 ± 2 | |
| 181–290 min/week (n = 408) | 234 ± 10 | 139 ± 8 | 9 ± 1 | 21 ± 4 | 14 ± 1 | 5 ± 1 | 37 ± 4 | 10 ± 2 | |
| ≥291 min/week (n = 347) | 219 ± 12 | 119 ± 8 | 8 ± 1 | 17 ± 3 | 12 ± 1 | 5 ± 1 | 37 ± 4 | 19 ± 7 | |
| p-value | 0.79 | 0.39 | 0.95 | 0.71 | <0.01 | 0.88 | 0.79 | 0.11 | |
| Resistance training duration | <46 min/week (n = 364) | 255 ± 11 | 157 ± 10 | 10 ± 2 | 17 ± 3 | 21 ± 2 | 7 ± 2 | 33 ± 4 | 10 ± 2 |
| 46–135 min/week (n = 426) | 215 ± 9 | 126 ± 7 | 7 ± 1 | 19 ± 4 | 16 ± 1 | 5 ± 1 | 35 ± 4 | 7 ± 2 | |
| 136–270 min/week (n = 342) | 213 ± 10 | 128 ± 9 | 9 ± 2 | 15 ± 3 | 15 ± 2 | 4 ± 1 | 34 ± 4 | 9 ± 3 | |
| ≥271 min/week (n = 319) | 222 ± 12 | 106 ± 7 | 8 ± 1 | 22 ± 5 | 11 ± 1 | 6 ± 1 | 48 ± 5 | 21 ± 7 | |
| p-value | 0.02 | <0.01 | 0.60 | 0.60 | <0.01 | 0.45 | 0.03 | 0.06 | |
| Sleep duration | ≤4 h/night (n = 55) | 372 ± 46 | 149 ± 35 | 13 ± 6 | 67 ± 24 | 25 ± 6 | 10 ± 7 | 72 ± 13 | 35 ± 13 |
| 5–6 h/night (n = 730) | 243 ± 8 | 138 ± 6 | 8 ± 1 | 19 ± 3 | 16 ± 1 | 6 ± 1 | 43 ± 3 | 13 ± 2 | |
| 7–8 h/night (n = 620) | 191 ± 6 | 118 ± 5 | 8 ± 1 | 13 ± 2 | 16 ± 1 | 4 ± 1 | 28 ± 3 | 4 ± 1 | |
| ≥9 h/night (n = 21) | 148 ± 25 | 75 ± 20 | 11 ± 9 | 7 ± 2 | 9 ± 4 | 17 ± 8 | 28 ± 10 | 1 ± 1 | |
| p-value | <0.01 | 0.03 | 0.52 | <0.01 | 0.18 | 0.05 | <0.01 | <0.01 | |
| Rank | Junior enlisted (n = 337) | 197 ± 11 | 93 ± 8 | 10 ± 2 | 23 ± 5 | 11 ± 1 | 8 ± 2 | 39 ± 4 | 12 ± 3 |
| Senior enlisted (n = 705) | 235 ± 8 | 126 ± 6 | 8 ± 1 | 20 ± 3 | 16 ± 1 | 6 ± 1 | 44 ± 3 | 15 ± 4 | |
| Warrant officer (n = 34) | 263 ± 39 | 149 ± 26 | 5 ± 3 | 16 ± 9 | 24 ± 7 | 5 ± 3 | 40 ± 14 | 25 ± 17 | |
| Junior officer (n = 214) | 210 ± 11 | 145 ± 9 | 5 ± 1 | 7 ± 1 | 17 ± 2 | 2 ± 1 | 31 ± 6 | 3 ± 1 | |
| Senior officer (n = 175) | 256 ± 13 | 191 ± 12 | 14 ± 3 | 14 ± 3 | 22 ± 3 | 3 ± 2 | 10 ± 3 | 3 ± 1 | |
| p-value | <0.01 | <0.01 | <0.01 | 0.06 | <0.01 | 0.05 | <0.01 | 0.09 | |
| Special Operations | No (n = 1419) | 227 ± 5 | 130 ± 4 | 8 ± 1 | 18 ± 2 | 16 ± 1 | 5 ± 1 | 37 ± 2 | 11 ± 2 |
| Yes (n = 40) | 198 ± 23 | 120 ± 22 | 5 ± 2 | 10 ± 3 | 17 ± 5 | 1 ± 0 | 41 ± 10 | 4 ± 4 | |
| p-value | 0.38 | 0.69 | 0.49 | 0.45 | 0.82 | 0.22 | 0.72 | 0.52 | |
| Service | Navy (n = 619) | 217 ± 7 | 136 ± 6 | 10 ± 1 | 15 ± 2 | 17 ± 1 | 4 ± 1 | 29 ± 3 | 7 ± 1 |
| Marine Corps (n = 846) | 232 ± 7 | 125 ± 5 | 7 ± 1 | 21 ± 3 | 15 ± 1 | 6 ± 1 | 43 ± 2 | 14 ± 3 | |
| p-value | 0.14 | 0.17 | 0.09 | 0.09 | 0.42 | 0.06 | <0.01 | 0.07 |
Abbreviations: SE = standard error.