Impact of Phenylketonuria-type Diet on Appetite, Appetite Hormones and Diet Induced Thermogenesis
Study Details
Study Description
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Phenylketonuria-type diet Breakfast: one pouch of amino acid supplement (174 mls supplemented drink PKU cooler 20, Vitaflo®; 20 g protein, 9.4 g carbohydrates, 0.7 g Fat) Lunch: cheese sandwich [low protein bread (Juvela, UK), no protein vegan cheese (Viotros, UK)], low protein crackers (Vitaflo, UK), and low protein cookies (Juvela, UK). Dinner: ad libitum buffet meal |
Dietary Supplement: Phenylketonuria-type diet
Breakfast, lunch and open buffet dinner
Other: Normal (control) diet
Breakfast, lunch and open buffet dinner
|
| Other: Normal diet Breakfast: 174 ml of milk (20 g protein, 9.4 g carbohydrates, 0.7 g Fat) Lunch: cheese sandwich, crackers, and cookies (regular foods) Dinner: ad libitum buffet meal |
Dietary Supplement: Phenylketonuria-type diet
Breakfast, lunch and open buffet dinner
Other: Normal (control) diet
Breakfast, lunch and open buffet dinner
|
Outcome Measures
Primary Outcome Measures
- 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)
- 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
- 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
Secondary Outcome Measures
- Taste perception of PKU supplements/foods [10 minutes]
Immediately after supplement ingestion and lunch consumption
- Consumption time for PKU supplements/foods [20 minutes]
Maximum 5 minutes for supplement ingestion and maximum 20 minutes for lunch consumption
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Healthy adult
-
Body weight stable for previous 4 months
-
Regular menstrual cycle (females)
Exclusion Criteria:
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Pregnancy or lactation (females)
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History of eating disorder
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History of gastrointestinal problems or surgery
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History of allergy
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History of chronic illness
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On any medication
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Smoking
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On nutritional supplements
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Following specific diet
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Currently taking part in other research
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Human Nutrition, School of Medicine, University of Glasgow | Glasgow | United Kingdom | G31 2ER |
Sponsors and Collaborators
- University of Glasgow
Investigators
- Study Chair: Dalia Malkova, PhD, University of Glasgow
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 200130139