Table 6.
Caffeine consumption (mean ± SE mg/day) of Navy 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 = 619) | 217 ± 7 | 136 ± 6 | 10 ± 1 | 15 ± 1 | 17 ± 1 | 4 ± 1 | 29 ± 3 | 7 ± 1 |
| Gender | Men (n = 447) | 232 ± 9 | 148 ± 8 | 6 ± 1 | 16 ± 3 | 19 ± 2 | 5 ± 1 | 33 ± 3 | 6 ± 1 |
| Women (n = 172) | 176 ± 10 | 106 ± 8 | 20 ± 3 | 9 ± 2 | 12 ± 2 | 2 ± 1 | 16 ± 3 | 11 ± 3 | |
| p–value | <0.01 | <0.01 | <0.01 | 0.15 | 0.04 | 0.07 | <0.01 | 0.10 | |
| Age (years) | 18–24 (n = 103) | 179 ± 20 | 90 ± 13 | 11 ± 3 | 18 ± 8 | 11 ± 2 | 6 ± 2 | 34 ± 7 | 9 ± 3 |
| 25–29 (n = 149) | 184 ± 12 | 101 ± 9 | 10 ± 2 | 13 ± 3 | 13 ± 2 | 5 ± 2 | 37 ± 6 | 6 ± 3 | |
| 30–39 (n = 215) | 231 ± 12 | 153 ± 11 | 8 ± 2 | 15 ± 4 | 21 ± 3 | 2 ± 1 | 25 ± 4 | 6 ± 2 | |
| ≥40 (n = 151) | 217 ± 7 | 179 ± 15 | 11 ± 3 | 12 ± 2 | 20 ± 3 | 4 ± 2 | 19 ± 5 | 9 ± 3 | |
| p–value | <0.01 | <0.01 | 0.72 | 0.80 | 0.03 | 0.20 | 0.07 | 0.81 | |
| Education | Some high school/high school graduate (n = 81) | 188 ± 22 | 96 ± 17 | 12 ± 4 | 9 ± 2 | 15 ± 5 | 5 ± 2 | 43 ± 10 | 7 ± 3 |
| Some college/Associate’s degree (n = 256) | 220 ± 12 | 127 ± 10 | 8 ± 2 | 21 ± 5 | 15 ± 2 | 5 ± 1 | 36 ± 4 | 9 ± 2 | |
| Bachelor’s/Graduate degree (n = 282) | 222 ± 10 | 156 ± 9 | 11 ± 2 | 11 ± 1 | 19 ± 2 | 2 ± 1 | 17 ± 3 | 5 ± 2 | |
| p–value | 0.32 | <0.01 | 0.41 | 0.06 | 0.25 | 0.16 | <0.01 | 0.38 | |
| Marital status | Single (n = 215) | 201 ± 13 | 111 ± 10 | 12 ± 2 | 14 ± 4 | 15 ± 2 | 6 ± 2 | 33 ± 4 | 10 ± 3 |
| Married (n = 404) | 225 ± 9 | 150 ± 8 | 9 ± 1 | 15 ± 2 | 18 ± 2 | 3 ± 1 | 26 ± 3 | 6 ± 1 | |
| p–value | 0.12 | <0.01 | 0.15 | 0.92 | 0.35 | 0.04 | 0.20 | 0.10 | |
| Race/ethnicity | White (n = 433) | 240 ± 9 | 152 ± 8 | 9 ± 1 | 16 ± 3 | 19 ± 2 | 4 ± 1 | 30 ± 3 | 9 ± 2 |
| Black (n = 70) | 117 ± 12 | 52 ± 8 | 14 ± 4 | 10 ± 3 | 11 ± 3 | 5 ± 1 | 22 ± 6 | 4 ± 2 | |
| Hispanic (n = 56) | 184 ± 17 | 112 ± 14 | 3 ± 1 | 13 ± 3 | 10 ± 2 | 2 ± 1 | 40 ± 9 | 3 ± 2 | |
| Other (n = 60) | 197 ± 24 | 142 ± 21 | 18 ± 6 | 7 ± 2 | 12 ± 5 | 1 ± 1 | 15 ± 6 | 2 ± 2 | |
| p–value | <0.01 | <0.01 | 0.02 | 0.55 | 0.07 | 0.57 | 0.13 | 0.23 | |
| Body mass index (kg/m2) | <25.0 (n = 211) | 190 ± 12 | 123 ± 10 | 15 ± 3 | 8 ± 1 | 16 ± 3 | 4 ± 1 | 21 ± 4 | 4 ± 1 |
| 25.0–29.9 (n = 300) | 230 ± 11 | 143 ± 9 | 8 ± 1 | 19 ± 4 | 16 ± 2 | 3 ± 1 | 31 ± 4 | 7 ± 2 | |
| ≥30.0 (n = 104) | 234 ± 18 | 141 ± 16 | 4 ± 1 | 13 ± 3 | 20 ± 3 | 5 ± 2 | 38 ± 7 | 14 ± 5 | |
| p–value | 0.03 | 0.27 | <0.01 | 0.10 | 0.66 | 0.81 | 0.05 | 0.04 | |
| Alcohol consumption | None (n = 107) | 195 ± 16 | 107 ± 13 | 12 ± 3 | 11 ± 3 | 21 ± 4 | 4 ± 1 | 34 ± 7 | 6 ± 3 |
| <1.34 g/day(n = 117) | 201 ± 16 | 112 ± 14 | 13 ± 4 | 14 ± 3 | 21 ± 4 | 7 ± 3 | 25 ± 6 | 8 ± 3 | |
| 1.34–3.99 g/day (n = 126) | 217 ± 18 | 144 ± 15 | 6 ± 1 | 18 ± 7 | 12 ± 2 | 3 ± 2 | 24 ± 5 | 9 ± 4 | |
| 4.00–8.93 g/day (n = 141) | 213 ± 13 | 149 ± 12 | 8 ± 1 | 9 ± 2 | 13 ± 2 | 3 ± 1 | 27 ± 5 | 4 ± 2 | |
| >8.93 g/day (n = 128) | 252 ± 18 | 159 ± 15 | 10 ± 3 | 21 ± 7 | 19 ± 3 | 3 ± 1 | 32 ± 6 | 9 ± 3 | |
| p–value | 0.11 | 0.03 | 0.22 | 0.40 | 0.10 | 0.34 | 0.70 | 0.61 | |
| Aerobic exercise duration | <101 min/week (n = 170) | 216 ± 13 | 132 ± 11 | 9 ± 2 | 14 ± 2 | 21 ± 3 | 2 ± 1 | 29 ± 5 | 9 ± 3 |
| 101–180 min/week (n = 151) | 210 ± 13 | 132 ± 12 | 13 ± 3 | 11 ± 2 | 22 ± 4 | 5 ± 2 | 25 ± 5 | 4 ± 2 | |
| 181–290 min/week (n = 178) | 229 ± 15 | 152 ± 12 | 9 ± 2 | 20 ± 7 | 11 ± 2 | 4 ± 2 | 27 ± 5 | 6 ± 2 | |
| ≥291 min/week (n = 118) | 210 ± 18 | 124 ± 15 | 9 ± 2 | 12 ± 2 | 14 ± 2 | 5 ± 2 | 35 ± 6 | 12 ± 4 | |
| p–value | 0.78 | 0.43 | 0.55 | 0.41 | 0.02 | 0.50 | 0.62 | 0.17 | |
| Resistance training duration | <46 min/week (n = 191) | 238 ± 13 | 159 ± 12 | 10 ± 2 | 13 ± 2 | 21 ± 3 | 3 ± 1 | 23 ± 5 | 9 ± 3 |
| 46–135 min/week (n = 204) | 205 ± 11 | 129 ± 10 | 10 ± 2 | 13 ± 2 | 18 ± 2 | 5 ± 2 | 26 ± 4 | 4 ± 1 | |
| 136–270 min/week (n = 123) | 222 ± 20 | 137 ± 16 | 12 ± 3 | 20 ± 7 | 13 ± 3 | 2 ± 1 | 32 ± 6 | 7 ± 3 | |
| ≥271 min/week (n = 95) | 192 ± 18 | 104 ± 11 | 6 ± 2 | 16 ± 9 | 10 ± 2 | 6 ± 3 | 40 ± 7 | 10 ± 4 | |
| p–value | 0.14 | 0.03 | 0.44 | 0.66 | 0.04 | 0.28 | 0.16 | 0.46 | |
| Sleep duration | ≤4 h/night (n = 14) | 353 ± 93 | 143 ± 65 | 7 ± 7 | 69 ± 59 | 30 ± 13 | 3 ± 2 | 76 ± 29 | 24 ± 14 |
| 5–6 h/night (n = 293) | 234 ± 11 | 148 ± 10 | 10 ± 2 | 15 ± 3 | 19 ± 2 | 4 ± 1 | 29 ± 3 | 10 ± 2 | |
| 7–8 h/night (n = 287) | 197 ± 9 | 127 ± 8 | 9 ± 1 | 12 ± 2 | 15 ± 2 | 4 ± 1 | 25 ± 4 | 4 ± 1 | |
| ≥9 h/night (n = 11) | 155 ± 30 | 86 ± 34 | 20 ± 17 | 7 ± 3 | 10 ± 7 | 9 ± 6 | 22 ± 11 | 0 ± 0 | |
| p–value | <0.01 | 0.29 | 0.53 | <0.01 | 0.32 | 0.82 | 0.02 | 0.04 | |
| Rank | Junior enlisted(n = 115) | 179 ± 17 | 101 ± 13 | 10 ± 2 | 11 ± 2 | 12 ± 2 | 6 ± 2 | 29 ± 6 | 9 ± 4 |
| Senior enlisted (n = 281) | 223 ± 12 | 129 ± 9 | 9 ± 1 | 19 ± 4 | 16 ± 2 | 4 ± 1 | 38 ± 4 | 8 ± 2 | |
| Warrant officer (n = 4) | 112 ± 41 | 50 ± 43 | 0 ± 0 | 24 ± 23 | 24 ± 19 | 0 ± 0 | 3 ± 3 | 11 ± 11 | |
| Junior officer (n = 110) | 203 ± 15 | 137 ± 13 | 4 ± 1 | 8 ± 2 | 21 ± 4 | 1 ± 0 | 26 ± 6 | 6 ± 3 | |
| Senior officer (n = 109) | 257 ± 17 | 193 ± 16 | 16 ± 4 | 13 ± 3 | 21 ± 4 | 4 ± 2 | 6 ± 2 | 4 ± 2 | |
| p–value | <0.01 | <0.01 | 0.06 | 0.38 | 0.28 | 0.28 | <0.01 | 0.71 | |
| Special Operations | No (n = 592) | 217 ± 8 | 138 ± 6 | 9 ± 1 | 15 ± 2 | 17 ± 1 | 4 ± 1 | 28 ± 3 | 7 ± 1 |
| Yes (n = 24) | 187 ± 22 | 98 ± 24 | 4 ± 2 | 11 ± 4 | 15 ± 7 | 0 ± 0 | 52 ± 15 | 6 ± 6 | |
| p-value | 0.42 | 0.22 | 0.32 | 0.73 | 0.77 | 0.32 | 0.06 | 0.92 |
Abbreviation: SE = standard error.