None listed
Conditions
Brief summary
The primary aim of the current study is to determine the effect of a moderate protein, high carbohydrate predominantly plant-based diet on appetite control and short-term health outcomes in individuals 65-75 years of age using a meal delivery based dietary intervention. 220 subjects, comprising equal numbers of men and women will be recruited. Participants will attend the RPA-CPC Clinic on 3 occasions. The first will be to attend a screening interview where they will be asked to complete questionnaires on their medical history, medications, cognitive health and eating behaviour. Eligible participants will then be invited to attend a baseline testing morning at the RPA-CPC Clinic. At the baseline testing, participants will arrive after an overnight fast with un-brushed teeth, bringing with them a 7d food diary, completed questionnaires about their lifestyle and general health, a stool sample and a 24hr urine collection. A blood sample will be collected and then an oral health examination will be performed and saliva and bacterial samples from tooth-surfaces will be collected. Body weight, waist and hip circumference, blood pressure, body composition and physical performance will also be measured. Participants will be randomly assigned to one of four dietary interventions. On the week after baseline testing study diets will be provided via a meal delivery company. Participants will be asked to consume the foods ad libitum. Participants will be requested to consume only from study foods and to keep a weighed food diary. During the 4 wk intervention, a study co-ordinator will contact each participant by phone on 5 different occasions. The first will be to ensure food has been delivered on the day before the study is to start, and the remaining 4 calls will be for a 48hr food recall. At the end of the final week of the dietary intervention participants will attend the RPA-CPC Clinic for final testing. At final testing, participants will arrive after an overnight fast with un-brushed teeth and will bring with them their study diary and a 24hr urine collection. A blood sample will be collected and an oral health examination will be performed and saliva and bacterial samples from tooth-surfaces will be collected. Measurements of body weight, waist and hip circumference, blood pressure, body composition and physical performance will be repeated.
Interventions
Eligible participants will be invited to attend a baseline testing morning at the RPA-CPC Clinic. Male and female subjects aged 65-75 years will be randomly assigned to one of four diets for 4wks. Each of the dietary interventions will be manipulated to provide 15% of energy as protein but will differ in the ratio of plant to animal proteins and the proportion of carbohydrate and fat.
The 4 dietary arms are as follows:
Arm 1: high plant to animal ratio (15% protein (38% plant, 62% animal), 61%
Eligible participants will be invited to attend a baseline testing morning at the RPA-CPC Clinic. Male and female subjects aged 65-75 years will be randomly assigned to one of four diets for 4wks. Each of the dietary interventions will be manipulated to provide 15% of energy as protein but will differ in the ratio of plant to animal proteins and the proportion of carbohydrate and fat. The 4 dietary arms are as follows: Arm 1: high plant to animal ratio (15% protein (38% plant, 62% animal), 61% carbohydrate, 24% fat) Arm 2: high plant to animal ratio (15% protein (18% plant, 82% animal), 48% carbohydrate, 37% fat) Arm 3: low plant to animal ratio (15% protein (18% plant, 82% animal), 61% carbohydrate, 24% fat) Arm 4: low plant to animal ratio (15% protein (38% plant, 62% animal), 48% carbohydrate, 37% fat) Prepared meals, snacks and fruit will be delivered once per week for 4 weeks to participants homes. Participants will be asked to eat ad libitum, to only consume study foods delivered to them and to keep a weighed food diary. Participants will be provided with scales and a food diary and will be asked to keep a weighed record of their intake. Participants will be asked to provide their own drinks and to avoid soft drinks and alcoholic beverages during the study. Each participant will be contacted by phone to ensure the first food delivery has been received and for 4 x 48hr food recalls during the intervention.
Sponsors
The University of Sydney
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
65 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
Females (post-menopausal) or males, 65-75 years, BMI 20-35kg/m2 will be recruited.
Exclusion criteria
Exclusion criteria will include diabetes mellitus (insulin dependent, Type 1 or 2), renal or liver disease, cancer or active neoplasms, hyperthyroidism (unless treated or under control), taking medications known to affect weight or energy expenditure, unintentional weight loss (>10% body weight) over the past 5 years, smoking, alcohol intake > 3 drinks/day, vegan and vegetarians, food allergies and/or intolerances, and when changes in diet are contraindicated by treating doctor.
Outcome results
None listed