Table 1.
Baseline characteristics of UK Biobank participants by smoking status
| Baseline characteristics a | Never smoking | Former smoking | Current smoking |
|---|---|---|---|
| Participants, n (%) | 53,381 (56.9) | 30,721 (32.7) | 9,760 (10.4) |
| Age in years, mean | 55.0 (8.1) | 56.9 (7.9) | 53.4 (8.0) |
| Men, % | 38.9 | 45.6 | 51.2 |
| Self-reported white background, % | 94.1 | 96.7 | 94.6 |
| Higher education, % | 49.7 | 47.1 | 41.1 |
| Current alcohol consumer, % | 80.0 | 86.8 | 79.5 |
| Ideal physical activity b, % | 61.2 | 62.5 | 59.5 |
| Intake of vegetable oil, % | 50.4 | 47.1 | 43.0 |
| ≥ 3 servings/day of fruit, % | 38.6 | 38.0 | 23.9 |
| ≥ 3 servings/day of vegetables, % | 8.0 | 9.8 | 8.3 |
| Oily fish intake in times/week, mean | 1.1 | 1.1 | 1.0 |
| Non-oily fish intake in times/week, mean | 1.2 | 1.2 | 1.1 |
| ≤ 2 servings/week of unprocessed meat, % | 69.5 | 69.2 | 64.0 |
| ≤ 1 serving/week of processed meat, % | 70.6 | 70.6 | 63.1 |
| Never consuming sugar-sweetened beverages, % | 14.0 | 15.6 | 14.0 |
| ≥ 3 servings/day of whole grain, % | 97.2 | 97.0 | 94.5 |
| Consuming refined grain at least weekly, % | 54.0 | 53.1 | 65.5 |
| BMI in kg/m2, mean | 26.8 | 27.3 | 26.5 |
| WHR, mean | 0.85 | 0.87 | 0.87 |
| Fasting hours, mean | 3.7 | 3.7 | 4.3 |
| Coffee intake in cups/day, mean | 1.8 | 2.1 | 2.8 |
| Tea intake in cups/week, mean | 3.4 | 3.4 | 3.7 |
| Family history of diabetes, % | 32.5 | 32.5 | 35.5 |
BMI: body mass index; WHR: waist-to-hip ratio;
a Means or proportions were estimated by adjusting for age and sex for all variables except the number of participants, age and sex
b An ideal level of physical activity is defined as ≥ 150 min/week of moderate or ≥ 75 min/week of vigorous or ≥ 150 min/week of mixed moderate and vigorous activity