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Whey Study

Principal Investigator: 

Professor Michelle McKinley


Name of the Study:

Whey Study - Effect of whey protein isolate (WPI) on secretion of GLP-1, appetite body weight and glycaemic control when delivered in enteric versus standard gelatin capsules: a randomised, placebo-controlled crossover study


Why is this Study important?

Whey is a by-product of yogurt and cheese making processes. Laboratory and animal studies suggest that whey protein isolate (WPI) could have a positive effect on energy intake and glucose tolerance and, via these mechanisms, may affect body weight and risk of type 2 diabetes. Recent studies have shown that whey can be used to manipulate gut function and, as a result, slow gastric emptying and stimulate the secretion of incretin hormones.


Research indicates that whey proteins may be most beneficial in terms of stimulating GLP-1 release when they are not digested by the stomach. Thus, providing whey in a form that protects its journey through the stomach, such as the form of an enteric coated capsule, may enhance its potential effects on appetite suppression, body weight and glycaemic control.


What is the Research question/aim?

The aim of study is to investigate the effect of WPI on secretion of GLP-1 appetite, body weight, body composition and glycaemic control in healthy young adults when it is delivered in an enteric coated capsule compared to delivery in a standard gelatin capsule


What the Study involves: 

The study involves three, two-week, treatment periods (random order) with a two week washout period in between taking the supplements (10 weeks in total). The two week supplement periods will be: placebo capsules (lactose monohydrate); WPI gelatin capsules; WPI enteric coated capsules.


Each participant will visit the NICRF six times in total. Three of the visits will involve an acute study to assess insulin, glucose and GLP-1 concentration after taking the WPI (this will be done at weeks 0, 4 and 8). A number of questionnaires will be completed over the period of the study as well as height, weight, waist circumference and blood measurements.



PPI Involvement: 

Not applicable



Who can take part in the Study?

Healthy adult volunteers aged between 18 and 30 years old can take part in this study. There are specific eligibility criteria that the research team will check to ensure the participants are eligible to take part.


Contact Information:


Joanna Shooter

Institute for Global Food Security

Queen's University Belfast

Cloreen Park



Professor Michelle McKinley

Centre for Public Health

School of Medicine, Dentistry & Biomedical Science

Institute Global Food Security


Grosvenor Road




NI Clinical Research Facility,
U Floor, Belfast City Hospital,
Lisburn Road, Belfast, BT9 7AB

Tel:+44 (0)28 9504 0342

Connect to the NICRF