Table 2 Caffeine consumption (mean ± SE mg/day) of consumers (≥1 time/week) by demographic, lifestyle, and military characteristics

Group

All (n = 23,175)

243.1 ± 1.5

166.6 ± 1.2

18.5 ± 0.4

15.8 ± 0.2

41.0 ± 0.6

1.0 ± 0.2

Gender

Men (n = 20,040)

250.7 ± 1.7

171.8 ± 1.5

17.5 ± 0.4

16.5 ± 0.2

43.9 ± 0.7

1.0 ± 0.2

Women (n = 3.135)

194.5 ± 3.0

133.8 ± 2.5

25.2 ± 0.9

11.5 ± 0.5

23.7 ± 1.3

1.2 ± 0.3

p-value (ANOVA)

< 0.01

< 0.01

< 0.01

< 0.01

< 0.01

0.60

Age

18–24 years (n = 3615)

203.6 ± 4.6

108.9 ± 2.7

19.5 ± 1.0

17.4 ± 0.7

56.0 ± 2.1

1.8 ± 0.6

25–29 years (n = 4746)

226.1 ± 3.1

147.7 ± 2.4

16.5 ± 0.7

13.1 ± 0.4

47.7 ± 1.5

1.0 ± 0.2

30–39 years (n = 9875)

254.7 ± 2.2

179.2 ± 1.8

17.3 ± 0.5

15.5 ± 0.3

42.0 ± 0.9

0.7 ± 0.2

≥40 years (n = 4821)

264.8 ± 3.4

201.6 ± 2.8

22.0 ± 0.8

18.0 ± 0.5

22.1 ± 1.1

1.1 ± 0.4

p-value (ANOVA/trend)

< 0.01/< 0.01

< 0.01/< 0.01

< 0.01/0.03

< 0.01/0.07

< 0.01/0.01

0.15/0.14

Formal Education

Some high school/high school graduate (n = 3099)

242.3 ± 4.8

129.3 ± 1.9

20.4 ± 1.3

20.9 ± 0.8

69.7 ± 2.5

1.9 ± 0.4

Some college/Associate’s degree (n = 9836)

243.3 ± 2.4

159.5 ± 1.7

18.1 ± 0.5

16.5 ± 0.4

48.3 ± 1.0

1.0 ± 0.3

Bachelor’s/Graduate degree (n = 10,234)

243.0 ± 2.1

184.8 ± 1.2

18.4 ± 0.5

13.6 ± 0.3

25.4 ± 0.8

0.8 ± 02

p-value (ANOVA/trend)

0.98/0.88

< 0.01/< 0.01

0.10/0.06

< 0.01/< 0.01

< 0.01/< 0.01

0.06/0.02

Race / Ethnicity

White (n = 14,827)

263.5 ± 1.9

184.8 ± 1.5

18.0 ± 0.4

17.3 ± 0.3

42.5 ± 0.8

0.8 ± 0.2

Hispanic (n = 3530)

227.7 ± 4.1

151.8 ± 3.0

15.9 ± 0.9

13.5 ± 0.6

45.3 ± 2.0

1.1 ± 0.3

Back (n = 2140)

158.8 ± 3.8

90.9 ± 2.7

21.5 ± 1.0

13.1 ± 0.7

31.1 ± 1.9

2.2 ± 0.5

Other (n = 2678)

217.5 ± 3.9

146.3 ± 3.1

22.0 ± 1.1

12.6 ± 0.6

35.3 ± 1.6

1.3 ± 0.3

p-value (ANOVA)

< 0.01

< 0.01

< 0.01

< 0.01

< 0.01

0.06

Body mass index

< 25.0 kg/m² (n = 6629)

215.7 ± 3.0

145.4 ± 2.0

19.2 ± 0.7

15.1 ± 0.4

34.3 ± 1.2

1.6 ± 0.5

25.0–29.9 kg/m² (n = 12,163)

251.2 ± 2.0

175.7 ± 1.7

17.7 ± 0.5

15.2 ± 0.3

42.0 ± 0.9

0.7 ± 0.1

≥30.0 kg/m² (n = 3956)

260.5 ± 3.5

172.3 ± 2.9

19.2 ± 0.9

19.1 ± 0.6

48.8 ± 1.5

1.1 ± 0.3

p-value (ANOVA/trend)

< 0.01/< 0.01

< 0.01/< 0.01

0.09/0.97

< 0.01/< 0.01

< 0.01/< 0.01

0.03/0.28

Aerobic exercise weekly duration

< 90 min/wk. (n = 6120)

235.7 ± 3.0

161.0 ± 2.2

17.8 ± 0.7

16.5 ± 0.4

39.2 ± 1.2

1.1 ± 0.4

90–180 min/wk. (n = 6560)

236.2 ± 2.4

165.3 ± 2.0

17.6 ± 0.6

16.5 ± 0.4

36.3 ± 1.0

0.6 ± 0.1

181–300 min/wk. (n = 5218)

249.1 ± 3.1

173.9 ± 2.5

17.5 ± 0.7

15.1 ± 0.4

42.0 ± 1.4

0.6 ± 0.1

> 300 min/wk. (n = 5277)

254.0 ± 3.9

167.7 ± 2.8

21.5 ± 0.7

14.9 ± 0.5

48.1 ± 1.6

1.8 ± 0.5

p-value (ANOVA/trend)

< 0.01/< 0.01

< 0.01/0.01

< 0.01/< 0.01

0.01/< 0.01

< 0.01/< 0.01

0.02/0.15

Resistance training weekly duration

≤45 min/wk. (n = 6650)

250.8 ± 3.0

172.8 ± 2.3

21.1 ± 0.7

20.6 ± 0.5

35.3 ± 1.2

1.0 ± 0.3

46–135 min/wk. (n = 5636)

239.3 ± 2.6

171.2 ± 2.3

18.3 ± 0.7

15.8 ± 0.4

33.5 ± 1.0

0.6 ± 0.1

136–300 min/wk. (n = 5859)

238.5 ± 2.7

166.8 ± 2.2

16.3 ± 0.6

13.5 ± 0.4

41.2 ± 1.2

0.8 ± 0.2

≥301 min/wk. (n = 5030)

242.3 ± 3.9

153.2 ± 2.7

18.0 ± 0.8

12.3 ± 0.4

56.9 ± 1.6

1.8 ± 0.5

p-value (ANOVA/trend)

0.01/0.06

< 0.01/0.01

< 0.01/< 0.01

< 0.01/< 0.01

< 0.01/< 0.01

0.05/0.08

Smoking

Never (n = 14,177)

215.5 ± 1.8

148.2 ± 1.4

18.7 ± 0.4

14.6 ± 0.3

33.0 ± 0.7

1.0 ± 0.2

Former user (n = 4475)

278.8 ± 3.4

198.4 ± 2.8

17.5 ± 0.8

15.6 ± 0.5

46.3 ± 1.4

0.9 ± 0.2

Current user (n = 4222)

298.7 ± 4.4

195.3 ± 3.2

19.1 ± 0.9

20.3 ± 0.6

62.7 ± 1.9

1.3 ± 0.5

p-value (ANOVA)

< 0.01

< 0.01

0.34

< 0.01

< 0.01

0.70

Smokeless tobacco use

Never (n = 17,597)

226.8 ± 1.6

155.8 ± 1.3

18.7 ± 0.4

15.6 ± 0.3

35.8 ± 0.7

1.0 ± 0.2

Former user (n = 1959)

294.5 ± 4.7

213.9 ± 4.1

16.5 ± 1.2

14.9 ± 0.7

48.6 ± 2.1

0.7 ± 0.3

Current user (n = 2938)

301.5 ± 5.4

195.9 ± 3.6

18.9 ± 1.3

18.2 ± 0.7

66.9 ± 2.4

1.6 ± 0.7

p-value (ANOVA)

< 0.01

< 0.01

0.20

< 0.01

< 0.01

0.32

Alcohol intake

0 ml/wk. (n = 6175)

218.9 ± 3.1

137.6 ± 2.4

19.5 ± 0.7

17.6 ± 0.5

39.5 ± 1.3

1.1 ± 0.3

0.23–24.85 ml/wk. (n = 5486)

214.8 ± 2.6

149.6 ± 2.2

18.2 ± 0.6

14.6 ± 0.4

29.8 ± 1.1

0.5 ± 0.1

24.86–71.69 ml/wk. (n = 5696)

239.0 ± 2.6

169.2 ± 2.2

17.2 ± 0.7

14.2 ± 0.4

35.3 ± 1.1

0.7 ± 0.2

≥71.70 ml/wk. (n = 5817)

299.2 ± 3.6

211.1 ± 2.6

19.3 ± 0.8

16.7 ± 0.5

45.8 ± 1.5

1.8 ± 0.5

p-value (ANOVA/trend)

< 0.01/< 0.01

< 0.01/< 0.01

0.05/0.60

< 0.01/0.17

< 0.01/< 0.01

0.02/0.13

Sleep

≥7 h/night (n = 8530)

221.8 ± 2.1

158.8 ± 1.7

17.3 ± 0.5

14.1 ± 0.3

29.0 ± 0.8

0.1 ± 0.0

5–6 h/night (n = 9110)

263.3 ± 2.4

177.4 ± 2.0

18.8 ± 0.6

17.7 ± 0.4

45.4 ± 1.0

0.2 ± 0.1

< 4 h/night (n = 918)

337.7 ± 11.9

199.4 ± 9.0

27.2 ± 2.6

21.2 ± 1.6

67.4 ± 4.7

6.4 ± 2.8

p-value (ANOVA/trend)

< 0.01/< 0.01

< 0.01/< 0.01

< 0.01/< 0.01

< 0.01/< 0.01

< 0.01/< 0.01

< 0.01/< 0.01

Rank

Junior enlisted, E1–E4 (n = 1869)

197.4 ± 6.9

103.3 ± 3.8

20.3 ± 1.5

18.3 ± 0.9

53.4 ± 2.9

2.0 ± 1.1

Mid enlisted, E4–E6 (n = 9891)

238.6 ± 2.3

148.0 ± 1.8

18.6 ± 0.6

16.6 ± 0.4

54.2 ± 1.1

1.2 ± 0.2

Senior enlisted, E7–E9 (n = 3971)

270.2 ± 4.2

194.1 ± 3.2

18.0 ± 0.9

17.2 ± 0.6

39.6 ± 1.6

1.3 ± 0.5

Warrant Officer (n = 537)

251.8 ± 8.2

190.0 ± 7.8

17.1 ± 2.0

12.8 ± 1.3

31.9 ± 3.1

0.1 ± 0.1

Junior officer, O1–O3 (n = 3436)

233.6 ± 3.4

179.7 ± 2.8

16.6 ± 0.8

10.5 ± 0.5

26.3 ± 1.4

0.4 ± 0.1

Senior officer, O4–O7 (n = 3471)

257.3 ± 3.1

206.1 ± 3.0

19.9 ± 0.8

16.4 ± 0.6

14.4 ± 0.9

0.4 ± 0.1

p-value (ANOVA)

< 0.01

< 0.01

0.09

< 0.01

< 0.01

0.10

Occupational assignment group

Combat arms (n = 6451)

260.7 ± 3.0

183.8 ± 2.4

16.8 ± 0.7

14.8 ± 0.4

44.3 ± 1.3

1.0 ± 0.2

Combat support (n = 10,424)

236.8 ± 2.4

158.7 ± 1.8

18.5 ± 0.6

15.9 ± 0.4

42.9 ± 1.0

0.8 ± 0.3

Combat service support (n = 9132)

238.1 ± 2.6

164.1 ± 2.1

19.6 ± 0.6

16.5 ± 0.4

36.6 ± 1.2

1.3 ± 0.3

p-value (ANOVA)

< 0.01

< 0.01

0.01

0.02

< 0.01

0.44

Service branch

Air Force (n = 8443)

215.0 ± 2.3

145.2 ± 1.7

17.7 ± 0.6

16.0 ± 0.4

35.9 ± 1.0

0.8 ± 0.3

Army (n = 6907)

251.5 ± 2.9

173.6 ± 2.3

18.6 ± 0.7

15.5 ± 0.6

42.0 ± 1.2

1.3 ± 0.3

Marine Corps (n = 2707)

269.7 ± 5.2

172.6 ± 3.9

16.7 ± 1.1

16.4 ± 0.5

63.7 ± 2.5

1.3 ± 0.4

Navy (n = 5118)

263.9 ± 3.0

189.4 ± 2.6

20.7 ± 0.7

15.8 ± 0.2

36.3 ± 1.2

1.0 ± 0.2

p-value (ANOVA)

< 0.01

< 0.01

< 0.01

0.36

< 0.01

0.58