None listed
Conditions
Brief summary
The ageing population is growing at a fast pace, and is associated with increased rates of common health issues such as cardiovascular disease, diabetes and obesity, however, optimal dietary intake can have a positive effect on these health issues most common in older age. Limited amounts of certain amino acids – namely branched-chain amino acid (BCAA: isoleucine, leucine and valine), tryptophan, methionine – have been linked with poor health outcomes in older age. In this study we aim to determine the effects of branched chain amino acids (BCAA) supplementation by itself, combined with tryptophan, or combined with methionine on appetite and short-term metabolic outcomes in individuals aged 65-80. We expect that that compared to the control diet, those on a diet supplemented with BCAA will have an increased appetite and energy intake, whereas those on a diet supplemented with BCAA and tryptophan will not show this increase in appetite. Supplementation of BCAA + methionine will have similar effect to BCAA on its own.
Interventions
Participants will be provided with ad libitum access to a standard diet containing 18-19% of energy as protein, 30-35% fat and up to 45-65% carbohydrate as per the Acceptable Macronutrient Distribution Ranges set by the NHMRC. A bottle of 1L of olive oil will be provided to participants to be used as salad dressing. Study diets will be provided via a meal delivery company (Kinela). Milk (up to 100mL a day), fresh fruit (up two serves of fruit a day) and vegetables (up to two cups of salad a day)
Participants will be provided with ad libitum access to a standard diet containing 18-19% of energy as protein, 30-35% fat and up to 45-65% carbohydrate as per the Acceptable Macronutrient Distribution Ranges set by the NHMRC. A bottle of 1L of olive oil will be provided to participants to be used as salad dressing. Study diets will be provided via a meal delivery company (Kinela). Milk (up to 100mL a day), fresh fruit (up two serves of fruit a day) and vegetables (up to two cups of salad a day) will also be allowed as additions to the diet provided and a list of approved additions and quantities will be provided. Those randomised to BCAA, BCAA+tryptophan and BCAA+methionine will be provided with supplements to be consumed in conjunction with their meals. All foods and supplements consumed will be recorded in the study food diary to be kept by each participant. Participants in the BCAA group will be provided with a sealed bottle containing 100 capsules of Solgar, BCAA Plus, Free Form Capsules which contains 540mg of L-leucine, 360mg of L-isoleucine and 300mg of L-valine each. Participants will be asked to consume one capsule, three times daily of this supplement along with their food (i.e. breakfast, lunch and dinner) for 4 weeks. Participants in the BCAA + tryptophan group will be provided with a sealed bottle containing 60 capsules of Now Foods L-Tryptophan, Double Strength which contains 1000 mg of L-tryptophan each and a sealed bottle containing 100 capsules of Solgar, BCAA Plus, Free Form Capsules which contains 540mg of L-leucine, 360mg of L-isoleucine and 300mg of L-valine each. Participants will be asked to consume one capsule, twice daily of the tryptophan supplement along with their main meals (i.e. lunch or dinner) and one capsule, three times daily of BCAA supplement along with their food (i.e. breakfast, lunch and dinner) for 4 weeks. Participants in the BCAA + methionine group will be provided with a sealed bottle containing 100 capsules of Now Foods L-Methionine which contains 500 mg of L-methionine each and a sealed bottle containing 100 capsules of Solgar, BCAA Plus, Free Form Capsules which contains 540mg of L-leucine, 360mg of L-isoleucine and 300mg of L-valine each. Participants will be asked to consume one capsule, three times daily of methionine and BCAA supplements along with their food (i.e. breakfast, lunch and dinner) for 4 weeks.
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 80 Years
Healthy volunteers
Yes
Inclusion criteria
Females (post-menopausal) or males, 65-80 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), schizophrenia, sleep apnea, taking medications known to affect weight or energy expenditure, antibiotics use in the previous four weeks, unintentional weight loss (>10% body weight) over the past 5 years, smoking, alcohol intake >3 standard drinks/day or unwilling to refrain from alcohol, vegan and vegetarians, food allergies and/or intolerances, and when changes in diet are contraindicated by treating doctor.
Outcome results
None listed