Table 1.
Participant characteristics by sleep duration category: young adults aged 20–30 years, Minneapolis/St. Paul metropolitan area of Minnesota, USA, 2008–2009, Project EAT (Eating and Activity in Teens and Young Adults)
| <7 h per night (N 203; 11·5 %) | 7–<8 h per night (N 471; 26·6 %) | 8–<9 h per night (N 642; 36·2 %) | ≥9 h per night (N 457; 25·8 %) | |||||
|---|---|---|---|---|---|---|---|---|
| Mean or n | sd or % | Mean or n | sd or % | Mean or n | sd or % | Mean or n | sd or % | |
| Demographics | ||||||||
| Age (years), mean and sd | 25·5 | 1·6 | 25·6 | 1·6 | 25·3 | 1·6 | 25·1 | 1·7 |
| Female, n and % | 87 | 42·8 | 240 | 51·0 | 366 | 57·0 | 292 | 64·0 |
| Race/ethnicity†, n and % | ||||||||
| White | 93 | 9·8 | 255 | 27·0 | 384 | 40·6 | 214 | 22·6 |
| Asian | 39 | 12·3 | 90 | 28·5 | 92 | 29·1 | 95 | 30·1 |
| Black | 44 | 16·1 | 64 | 23·1 | 82 | 29·6 | 86 | 31·1 |
| Hispanic | 9 | 10·0 | 27 | 30·2 | 37 | 40·8 | 17 | 19·1 |
| Mixed/Other | 15 | 12·1 | 31 | 23·9 | 43 | 33·4 | 39 | 30·6 |
| Education†, n and % | ||||||||
| Less than high school | 11 | 16·2 | 8 | 11·2 | 18 | 25·7 | 32 | 46·9 |
| High school/GED | 86 | 12·8 | 178 | 26·6 | 216 | 32·2 | 191 | 28·4 |
| Vocational or associates degree | 60 | 13·4 | 115 | 25·6 | 153 | 33·9 | 122 | 27·1 |
| College graduate | 45 | 7·8 | 169 | 29·0 | 255 | 43·9 | 112 | 19·2 |
| Married, n and % | 38 | 18·6 | 131 | 28·1 | 166 | 25·9 | 83 | 18·1 |
| Behavioural characteristics, mean and sd | ||||||||
| Physical activity (h MVPA/week) | 4·4 | 4·1 | 4·1 | 3·9 | 4·3 | 4·0 | 3·5 | 3·6 |
| Depression scale | 19·2 | 4·7 | 17·9 | 5·1 | 18·0 | 4·9 | 19·0 | 4·6 |
| BMI (kg/m2), mean and sd | 27·6 | 5·5 | 26·3 | 5·6 | 26·1 | 6·3 | 26·6 | 6·1 |
| Outcomes | ||||||||
| Caffeinated drinks per day‡ | 0·9 | 1·2 | 0·7 | 1·0 | 0·7 | 1·0 | 0·7 | 1·1 |
| Sugar-sweetened beverages per day§ | 1·1 | 1·3 | 0·8 | 1·2 | 0·8 | 1·1 | 0·9 | 1·4 |
| Sugar-free beverages per day║ | 0·4 | 1·0 | 0·4 | 0·8 | 0·4 | 0·8 | 0·3 | 0·8 |
| Breakfast consumption per week | 3·6 | 2·2 | 3·9 | 2·4 | 4·2 | 2·5 | 3·6 | 2·4 |
| Fast food consumption per week | 1·7 | 1·7 | 1·5 | 1·7 | 1·5 | 1·7 | 1·7 | 1·6 |
| Energy drinks¶ | 52 | 25·7 | 79 | 16·9 | 111 | 17·3 | 76 | 16·6 |
| Sports drinks¶ | 76 | 37·4 | 161 | 34·2 | 178 | 27·7 | 120 | 26·4 |
GED, General Educational Development; MVPA, moderate–vigorous physical activity.
Row percentages.
Caffeinated beverages were defined as low-calorie beverages with caffeine (e.g. Diet Coke, Diet Mountain Dew), carbonated beverages with caffeine and sugar (e.g. Coke, Pepsi, Mountain Dew, Dr. Pepper), tea with caffeine including green tea, coffee with caffeine and dairy coffee drink (e.g. cappuccino).
Sugar-sweetened beverages were defined as carbonated beverages with caffeine and sugar, other carbonated beverages with sugar (e.g. 7-Up, Root Beer, Ginger Ale, Caffeine-Free Coke) and other sugared beverages (punch, lemonade, sports drinks or sugared ice tea).
Sugar-free beverages were defined as low-calorie beverages with caffeine and other low-calorie beverages without caffeine (e.g. Diet 7-Up).
Energy and sports drink consumption defined as at least one drink per week v. less than one drink per week.