A cross-sectional study with repeated measurements among healthy Danish adults to assess the validity and reproducibility of a self-administered 7-day web-based dietary assessment tool, myfood24® tested against objective biomarkers.

Healthy volunteers (age 35-70 yrs; BMI 22-32) will be recruited for the study. Informed consent will be obtained and participants will complete a self-administered web-based 7-day 24-hour dietary recall tool (myfood24®).Validity of this dietary registration tool will be assessed by comparing the estimated intake of selected nutrients (protein, energy) and selected food groups (fruit and vegetables, whole grain, coffee, alcoholic beverages) against objective biomarkers obtained from a 24-hour urine sample, through a measurement of resting energy metabolic rate, and from a fasting blood sample, respectively. Reproducibility will be assessed by comparison of the results from two self-administered web-based 7-day 24-hour dietary recalls obtained 4 weeks (± 1 weeks) apart.

Inclusion criteria:

• Apparently healthy adults between 35 and 70 years old
• Body mass index (BMI) between 22-32 kg/m2
• Weight stable defined as gain or loss of < 2.5% body weight during the past 3 months;
• Willingness to maintain current dietary and physical activity habits throughout the study period.
• Have high-speed internet access;
• Able to speak, read and write Danish;
• Willing to visit the Department of Nutrition, Exercise, and Sports (NEXS).

Exclusion Criteria:

• Clinically diagnosed chronic disease,
• use of corticosteroids or other medication that would potentially affect the nutrient metabolism or excretion of biomarkers of interest,
• presence of food allergy or intolerance that requires a special diet,
• pregnancy and lactation,
• excess physical activity (>5h/week of high intensity),
• current participation in another trial

Healthy Danish adults