Table 3.
Potential confounding variables that will be assessed
| Potential confounding variables | |
| Comorbidities | Number of comorbidities |
| Alcohol use | Non-drinker |
| Moderate drinker | |
| (Women: 1–14 glasses/week) | |
| (Men: 1–21 glasses/week) | |
| Heavy drinker | |
| (Women:>14 glasses/week) | |
| (Men:>21 glasses/week) | |
| Smoking | Never smoked |
| Former smoker | |
| Current smoker | |
| Body mass index (BMI) | BMI calculated by dividing body weight (kg) by height (m²) |
| Medication use | Type and number of medications used |
| Drugs use | Recreational drugs use |
| Yes | |
| No | |
| Visceral Adipose Tissue79 80 | Linear distance between abdominal peritoneum and ventral aspect of vertebrae will be assessed using ultrasonography |
| Physical activity | International Physical Activity Questionnaire, expressed in 1000 metabolic equivalent minutes per week (Dutch version) |
| Menstrual cycle81 | Regular menstrual cycle (yes/no), whether women are in the luteal or follicular stage (yes/no), menopause (yes/no) and post menopause (yes/no) |
| Season82 | Timing of experiment (summer, autumn, spring or winter) |
| Age | Age in years |
| Psychological status74 | Mental health inventory-5 |
| Intervention expectations42 | The extent to which they agree (using a four-point Likert scale) with four statements (online supplemental appendix 3) |