Testing of the protein leverage hypothesis (PLH): effect of percent dietary protein on total energy intake in lean healthy adults

• Register: ANZCTR
• Last refreshed on: 13 January 2020
• Main ID: ACTRN12616000144415
• Date of registration: 08/02/2016
• Prospective Registration: No
• Primary sponsor: The University of Sydney
• Public title: Testing of the protein leverage hypothesis (PLH): effect of percent dietary protein on total energy intake in lean healthy adults
• Scientific title: Testing of the protein leverage hypothesis (PLH): effect of percent dietary protein on total energy intake in lean healthy adults
• Date of first enrolment: 10/01/2008
• Target sample size: 24
• Recruitment status: Completed
• URL: https://anzctr.org.au/ACTRN12616000144415.aspx
• Study type: Interventional
• Study design: Purpose: Prevention; Allocation: Randomised controlled trial; Masking: Blinded (masking used);Assignment: Crossover;Type of endpoint: Efficacy;
• Phase: Not Applicable

Countries of recruitment

Australia

Contacts

• Name: Dr Alison Gosby

• Name: Dr Alison Gosby

Key inclusion & exclusion criteria

Inclusion criteria: Lean, healthy male and female participants.

Exclusion criteria: Exclusion criteria included diabetes, high blood pressure, gastrointestinal problems, asthma, eczema or hay fever, chronic medical conditions, anaemia, allergies or strong dislikes to any study foods, smoking, following a weight reducing diet within the 3 months prior to the screening interview, pregnancy and breastfeeding, a history of eating disorders or irregular eating habits. Vegetarian and vegans were excluded to aid in preparation of the intervention foods.

Age minimum: 18 Years
Age maximum: 65 Years
Gender: Both males and females

Health Condition(s) or Problem(s) studied

obesity;
obesity

Diet and Nutrition - Obesity

Intervention(s)

Each participant attended three 4-day periods of in-house dietary manipulation. Participants were given ad libitum access to diets containing 10%, 15% and 25% protein over the three 4day periods. Carbohydrate was adjusted to be 60, 55 and 45% energy and dietary fat was kept constant at 30%. Food intake was measured by recording the weight of the food before and after serving, to the nearest gram. Energy intake was calculated using the nutritional information for each recipe. The trial was a randomised crossover-trial, each participant completed each of the three 4-day interventions with at least a one week washout period between interventions.

Primary Outcome(s)

Energy intake (MJ): Participants were given ad libitum access to study food with no access to other foods during each intervention period. Participants were offered 3 main meals at a designated time each day and had free access to additional study snack foods. Participants were asked to leave any uneaten snack foods and/or empty packages in a designated fridge. Food intake was measured by recording the weight of the food before and after serving to the nearest gram. Total energy intake was then calculated using the nutritional information for each recipe.[Weight of food was measured immediately before and after each main meal for each 4-day treatment period. Snack food was weight at the beginning of each day and was monitored and weighed by the study coordinator every 2 hours from 7.30am until 7.30pm. Any leftover or empty packages from snacks consumed overnight (7.30pm-7.30am) were weighed at 7.30am the next day. ]

Secondary Outcome(s)

Serum levels of total cholesterol[Measured at baseline and on the morning of day 5 following each of the three 4 day interventions.]

24 hour levels of urinary urea[Measured the day prior to and on day 4 of each of the three interventions.]

Plasma levels of Cholecystokinin[Measured on the morning of day 5 following each of the three 4 day interventions.]

Serum levels of glucose[Measured at baseline and on the morning of day 5 following each of the three 4 day interventions.]

Serum levels of triglycerides[Measured at baseline and on the morning of day 5 following each of the three 4 day interventions.]

Food palatability using visual analogue scales[Questionnaires were administered for each food provided on day 4 of each of the 4 day interventions.]

Plasma levels of Glucagon Like Polypeptide 1 protein[On the morning of day 5 following each of the three 4 day interventions.]

Plasma levels of total Ghrelin protein[On the morning of day 5 following each of the three 4 day interventions.]

Serum levels of HDL cholesterol[Measured at baseline and on the morning of day 5 following each of the three 4 day interventions.]

Blood pressure was measured by Omron Standard Blood Pressure Monitor.[Measured at baseline and on the morning of day 5 following each of the three 4 day interventions]

Glucose control measured by Continuous Glucose Monitoring System[Measured throughout each of the three 4 day interventions.]

Appetite rating using visual analogue scales[Appetite questionnaires were administered hourly from breakfast until 22:00.]

Body mass was measured by digital scales.[Measured at baseline and on the morning of day 5 following each of the three 4 day interventions.]

Plasma levels of Fibroblast Growth Factor 21 protein.[Measured at baseline and on the morning of day 5 following each of the three 4 day interventions ]

Secondary ID(s)

nil known

Source(s) of Monetary Support

National Health and Medical Research Council

Secondary Sponsor(s)

Alison Gosby

Ethics review

Status: Approved
Approval date:
Contact:

Sydney Local Health District

Status: Approved
Approval date:
Contact:

The University of Sydney Human Research Ethics Committee