Quotes of prof. Blaak:

‘Without wishing to brag, I would say that our department knows a great deal about the human metabolism. We are known for this all over the world’

‘We want to find out as much as we can about the human metabolism, so that we’ll be more and more able to prevent diseases and health risks’



They already existed back in the 1980s but over the past two decades have undergone substantial improvements. Nowadays they are so good that they are purchased by researchers from all over the world for huge amounts of money. After construction and testing in Maastricht, they are shipped from Limburg to every corner of the world and assembled on-site by experts from Maastricht University’s Department of Human Biology and Maastricht Instruments BV, a subsidiary of the Faculty of Health, Medicine and Life Sciences and Maastricht University Holding B.V. We’re talking about the ultra-modern respiration chambers that were developed by Paul Schoffelen from Maastricht University’s Department of Human Biology, and which are used to investigate your metabolism and the rate at which you expend energy.


Locked up

In these rooms we can measure how much energy you use and where this energy comes from. Are you burning fat, carbohydrates or protein? If you know how much energy you use, you can calculate how much food you need. This will give you more insight into the role of nutrition in maintaining a healthy weight, and enable you to prevent overweight, diabetes and other related health issues. The respiration chambers, or room calorimeters, can also be used to analyse the impact of the environment and physical activity. All sorts of environmental factors can be explored, from climate and sleeping patterns to top-level sport or altitude simulation. Research involving respiration chambers focuses on the impact of nutrition and the environment on our health.

Besides any air pumped in or out, a respiration chamber is a fully airtight circuit. A test subject will spend anywhere from a few hours to as much as a week in the respiration chamber. The door cannot be locked, but does need to remain closed during the experiment. Meals are served through a hatch, urine samples are collected in containers and analysed, and faeces is frozen in a deep-freeze toilet. Fresh filtered outside air is pumped into the room, and exhaled air is extracted from it. These incoming and outgoing airflows are analysed to determine the test subject’s energy expenditure.



In Maastricht, the calorimeters form part of the Metabolic Research Unit Maastricht (MRUM). Professor Ellen Blaak from the Department of Human Biology & Movement Sciences is one of the researchers who supervise research projects which make use of the respiration chambers and other high-tech spaces. ‘At the MRUM [pronounced ‘emrum’], we have a number of different high-tech spaces: the one-person respiration chambers, but also chambers to measure physical exertion, resting metabolic rate and body composition, and for doing nutritional research. In some of the rooms, a number of people can stay at the same time. We use them not just for measuring energy expenditure, but also to do research into metabolic disorders that increase the risk of diabetes and cardiovascular disease. We regularly work with the Maastricht UMC+, for example when medical procedures are taking place. Initially, only the Department  of Human Biology & Movement Sciences made use of the MRUM. Now other departments and the MUMC+ are using it as well, Maastricht University Medical Centre’s departments of Internal Medicine, Pulmonology and Gastro-Enterology for example. This broad cooperation benefits everyone involved.’


Test subjects

‘We work predominantly with test subjects who have an increased risk of diabetes, cardiovascular disease, COPD or gastrointestinal problems, but also with healthy people of all different ages and with fitness levels ranging between untrained and professional athlete. We want to find out as much as possible about the human metabolism, so that, increasingly, we can prevent diseases and health risks. The test subjects tend to experience their stay as being very positive. For example, they get a balanced diet and useful advice. Weight-loss programmes are very popular. Participants undergo extensive examinations before and after the study so they know exactly where they’re at. One of the ways we recruit test subjects is by placing ads in weekly magazines. They receive modest financial compensation, but often they take part simply because they feel that the research is important, or because their health stands to benefit from it. Their participation is very important for us to achieve our objective of fostering a healthy region. Of course, the findings of our research are also disseminated to the outside world to make sure they are implemented in practice. We also work with the food industry. For example, if we discover that certain fibres have a positive impact on metabolism, the food industry can use this knowledge to develop products. I feel safe in saying that our department knows a great deal about the human metabolism. We have come to be known for this all over the world.’


Hotel room

‘Staying in a respiration chamber may sound very claustrophobic, but it’s really not that bad. Most test subjects quite like it. There is a window, so you can look outside, and the rooms have all the mod cons. You’ve got your own deep-freeze toilet, washbasin and bed. There is a television, an internet connection and a desk. It’s very rare for test subjects to suddenly want to leave the respiration chamber—especially as the door isn’t locked and staff are always available on-site. As part of my own research several years ago, children as young as eleven and twelve spent several days in the respiration chamber. They loved it, because they got to bring a friend. The friend was put in the respiration chamber next door. They could communicate with each other constantly, talk on the phone as much as they wanted and spend the entire evening watching television without their parents getting on their case. As a researcher, you develop a bond with your test subjects. You bring them their meals and stay in contact with them. That’s very important for both us and them.’


For more information, click here:

http://www.straitstimes.com/singapore/scientists-seek-to-boost-health-of-asians-by-modifying-food  http://www2.warwick.ac.uk/services/ris/impactinnovation/impact/analyticalguide/wbc/

Professor Ellen Blaak

Professor Ellen Blaak has been working for Maastricht University since 1989. She started out as a PhD candidate in the Department of Human Biology and continued to work there, with a number of stays abroad in the interim. In 2007 she was appointed professor at the department and is currently Professor of the Physiology of Fat Metabolism there.


Original publication: Hecht november 2016 – year 1, nr3

Text: Margot krijnen

Photography: Appie Derks