Assessing oxidative stress caused by a meal in healthy males

This study is a single arm intervention study. The study requires healthy male participants to make two visits to the testing facility. The first visit is a screening visit where eligible participants will also have their height, weight, waist circumference and body composition measured by a researcher trained in collecting anthropometric measures. At this visit participants will also provide the research team with basic demographic information (age, sex, ethnicity). The second visit, designated as the testing visit, has participants attending the testing facility from 8:00 am to 5:00 pm. Participants will arrive to this visit following an overnight fast after consuming a standardised dinner meal the night before (participants are provided with a pre-prepared meal, which is to be re-heated in the microwave), between 7:00 and 9:00 pm. Participants will also be asked to avoid a list of foods high in antioxidants and avoid strenuous exercise for the 24 hours prior to the beginning of the testing session. Participants will receive reminders via text message prior to the testing session to remind them of these requirements. During the testing visit, the participants will have a cannula inserted into a vein in their arm by a nurse, for multiple blood draws. Participants will also have capillary blood samples taken during the testing visit, via finger pricks. Following a two hour run-in period, including venous and capillary blood sampling, participants are given a high fat high carbohydrate challenge meal (48% carbohydrates, 39% fat; smoothie containing ~50% of daily estimated energy requirements based on participant weight) to consume within 10 minutes (time 0). Following this, venous blood samples will be collected every 15 minutes for the first hour, every 30 minutes for the following two hours, and then every 60 minutes up to 6 hours following the meal. Finger prick blood samples will be collected 30 and 60 minutes following the meal. All blood samples will be taken by a nurse or by researchers trained in phlebotomy. During the testing visit participants will also be asked to complete a series of questionnaires about the food intake and physical activity. With the guidance of the researchers, participants will complete a food frequency questionnaire with a focus on high antioxidant foods, a 24-hour food recall to asses their usual intake and compliance with consuming the standardised dinner meal, and the International Physical Activity Questionnaire (IPAQ) to assess their participation in walking, moderate and vigorous physical activity.