2.7. Participants
Fifteen healthy volunteers were recruited for the study by means of advertisements, flyers, and personal communications.
Potential volunteers were briefed on all aspects of the study and were allowed to ask questions before giving written formal consent.
Volunteers participated in a health assessment which included anthropometric measurements (height, weight, waist-to-hip ratio, Tanita BC-418MA segmental body
composition analysis) and filled in a health questionnaire (asking about medications, vitamin and mineral supplement use, previous and present diseases, smoking habits, and allergies).
If volunteers fulfilled the acceptable criteria (body mass index: 18.5-29.99 kg/m2; age, 18-65 years; fasting blood glucose, 4-6 mmol/L; not on prescription medication; nonsmoking; no genetic or metabolic diseases), they were given a food frequency questionnaire (FFQ) to complete with regard to their average food intake over the previous 3 months, and they participated in a 24-hour dietary recall given by qualified personnel. Each volunteer was asked to avoid the consumption of caffeine, alcohol, nicotine, marijuana, or any other drugs and strenuous exercise on the evening prior to each trial, and to ensure that their food intake was as similar as possible for the 18 hours before all trials.
Testing began each morning between 7:30 AM and 9:30 PM after an overnight fast
(10-12 hours).
The present study was conducted according to the guidelines laid down in the Declaration of Helsinki, and all procedures involving human volunteers were approved by the University Research Ethics Committee at Oxford Brookes University.