None listed
Conditions
Brief summary
Intermittent fasting (IF) is any strategy where participants severely restrict caloric intake on one or more days of the week with 'normal' eating on non-fasting days, and has recently gained popularity for weight loss. Intermittent fasting compares well with other traditional nutritional interventions such as long term calorie restriction, with higher levels of dietary adherence reported over time. High intensity interval training (HIIT) has also been reported as an effective and time efficient exercise strategy for weight loss, as well as improvements to markers of cardiovascular and metabolic disease. Individually IF and HIIT are effective, however, their combined effects are unknown. This study intends to examine the short and long term impacts of IF, specifically a 2:5 ratio of fasting days to normal eating days, and HIIT on weight loss and cardio vascular and metabolic health. The influence of these interventions will be monitored separately, or in combination, on body composition, metabolic and cardiovascular health, fitness and quality of life. In addition, the study will identify changes in serum miRNA’s expression. To achieve these aims, overweight and obese individuals will undergo 1 of 3, 16 week interventions including: 1) 5:2 diet intermittent fasting diet, 2) supervised high intensity interval training (HIIT) performed 3 days a week, and 3) a combination of both interventions. Body composition, arterial stiffness, blood pressure, aerobic capacity (VO2 max) and quality of life will be measured at 0, 8 and 16 weeks. Additionally, blood samples will be taken and measured for lipid profiles, fasting plasma glucose, insulin resistance, markers of inflammation and expression levels of microRNA. Participants will also be asked to continue the interventions for a further period of 8 months self-directed, with follow up measurements performed at the 24, 36 and 52 weeks. Effective dietary and exercise interventions that promote long-term adherence and sustained beneficial effects on metabolic and disease markers are required to reduce the increasing rates of obesity.
Interventions
Participants will undergo one of three, 16 week interventions including: 1) 5:2 diet intermittent fasting diet, 2) supervised high intensity interval training (HIIT) performed 3 days a week, and 3) a combination of both interventions. The 5:2 intermittent fasting diet will involve participants fasting for two non-consecutive days of the week, consuming a single meal of 500kcal for women or 600kcal for men and then fasting for 24 hours. For the remaining five days of the week participant’s
Participants will undergo one of three, 16 week interventions including: 1) 5:2 diet intermittent fasting diet, 2) supervised high intensity interval training (HIIT) performed 3 days a week, and 3) a combination of both interventions. The 5:2 intermittent fasting diet will involve participants fasting for two non-consecutive days of the week, consuming a single meal of 500kcal for women or 600kcal for men and then fasting for 24 hours. For the remaining five days of the week participant’s dietary intake is unrestricted. Dietary compliance will be monitored weekly using a food diary to record intake on both fasting and non-fasting days. The HIIT protocol used involves 3-6 cycles of 20s cycling at 150% VO2Max followed by 40s of active rest, with 3 minutes of warmup and 3 minutes of warm down with no resistance. The high intensity interval training will be performed in small groups (3-5 participants) supervised by two investigators or personal trainers, and will be performed on bicycle ergometers. Participants will be required to complete at least 42 out of 48 HIIT sessions, with attendance and performance data (Maximum heart rate and heart rate at the completion of each interval) being recorded at each session using data collection forms. Body composition, arterial stiffness, blood pressure, aerobic capacity (VO2Max) and quality of life (mood state questionnaire) will be measured at 0, 8 and 16 weeks. Additionally, blood samples will be taken and measured for lipid profiles, fasting plasma glucose, insulin resistance, markers of inflammation and expression levels of microRNA. Participants will also be asked to continue the interventions for a further period of 8 months self-directed, with follow up measurements performed at the 24, 36 and 52 weeks.
Sponsors
Victoria University
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 35 Years
Healthy volunteers
No
Inclusion criteria
Overweight or obese but otherwise healthy
Exclusion criteria
Pregnancy Receiving treatment for high cholesterol Type 1 or 2 Diabetes Hypertensive Participation in another exercise or dietary study
Outcome results
None listed