Phenylketonuria (PKU)
Conditions
Keywords
low Phenylalanine diet, PKU supplements, diet induced thermogenesis, appetite, body weight
Brief summary
Low-phenylalanine diets are commonly prescribed to people with phenylketonuria (PKU), an inborn disease which causes accumulation of amino acid phenylalanine (Phe) in the blood. High blood Phe levels can cause mental, behavioural, neurological, and physical problems. Thus, low-phenylalanine diets help patients to manage their condition but it is not clear whether they have an impact on appetite, energy intake and changes in body weight. This is important to explore as prevalence of obesity in this population is rising high. This study aims to find out the effect of PKU-type meals on appetite, appetite biomarkers, and post-meal energy expenditure. The investigators will recruit 26 healthy adults and ask them to participate in two experimental trials. On one occasion the participants will be asked to consume a PKU-supplemented drink followed by a PKU type-lunch and on another occasion the supplement and lunch will be based on normally consumed foods. Series of blood samples will be taken and appetite will be assessed during both experiments. Both experimental trials will finish with consuming an all-you-can-eat buffet.
Interventions
DIETARY_SUPPLEMENTPhenylketonuria-type diet
Breakfast, lunch and open buffet dinner
OTHERNormal (control) diet
Breakfast, lunch and open buffet dinner
Sponsors
University of Glasgow
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
1. Healthy adult 2. Body weight stable for previous 4 months 3. Regular menstrual cycle (females)
Exclusion criteria
1. Pregnancy or lactation (females) 2. History of eating disorder 3. History of gastrointestinal problems or surgery 4. History of allergy 5. History of chronic illness 6. On any medication 7. Smoking 8. On nutritional supplements 9. Following specific diet 10. Currently taking part in other research
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diet induced thermogenesis | 300 minutes | Metabolic rate by means of computerised open-circuit ventilated hood system collected at baseline and after each blood sample collection for the duration of 20 minutes |
| Appetite hormone: ghrelin | 300 minutes | Plasma concentration at baseline (0 minute) and after ingestion of supplement (at 30, 60 and 90 minutes) and lunch (at 120, 150,180, 210, 240, 270 and 300 minutes) |
| Subjective appetite score | 300 minutes | Visual analogue scale (VAS) collected at baseline and after each blood sample collection |
| Appetite hormone: peptide YY (PYY) | 300 minutes | Plasma concentration at baseline (0 minute) and after ingestion of supplement (at 30, 60 and 90 minutes) and lunch (at 120, 150,180, 210, 240, 270 and 300 minutes) |
| Appetite hormone: glucagon-like peptide-1 (GLP-1) | 300 minutes | Plasma concentration at baseline (0 minute) and after ingestion of supplement (at 30, 60 and 90 minutes) and lunch (at 120, 150,180, 210, 240, 270 and 300 minutes) |
| Appetite hormone: cholecystokinin (CCK) | 300 minutes | Plasma concentration at baseline (0 minute) and after ingestion of supplement (at 30, 60 and 90 minutes) and lunch (at 120, 150,180, 210, 240, 270 and 300 minutes) |
| Appetite hormone: insulin | 300 minutes | Plasma concentration at baseline (0 minute) and after ingestion of supplement (at 30, 60 and 90 minutes) and lunch (at 120, 150,180, 210, 240, 270 and 300 minutes) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Consumption time for PKU supplements/foods | 20 minutes | Maximum 5 minutes for supplement ingestion and maximum 20 minutes for lunch consumption |
| Taste perception of PKU supplements/foods | 10 minutes | Immediately after supplement ingestion and lunch consumption |
Countries
United Kingdom
Outcome results
None listed