Precision Nutrition- Food for Thought?


In our Zoom for Thought on June 15th, 2021, UCD Discovery director Prof. Patricia Maguire spoke to Lorraine Brennan, Full Professor of Human Nutrition at University College Dublin, about  “Precision Nutrition - Food for Thought?”.  In case you missed it, here are our Top Takeaway Thoughts and a link to the video.


 Precision Nutrition


The concept of Precision Nutrition has emerged in recent years through work carried out by Lorraine’s team in UCD, among others. 

“Essentially what we started to notice was that individuals respond very specifically to a food but that response might be very different for the next individual.”

Though two people can eat the same breakfast and respond very differently, each will individually have a predictable response to that breakfast over time. 

“We say that the ‘within-individual response’ to food is very consistent, but the ‘between-individuals response’ is highly variable. We call this ‘high inter-individual variability.’”

Lorraine and her team are trying to understand the basis for this in order to deliver nutritional advice to individuals that is more tailored to their specific requirements.


Ultimate Goal


Lorraine’s team has examined people’s responses to food over the course of a day using continuous glucose monitors attached to the arm. 

“We have fed individuals breakfast with different types of protein in that breakfast and looked to see if there is a difference at an individual level in how they respond to the breakfast and the type of protein.” 

While individuals are “very reproducible”, they are very different from each other. 

“What we would fundamentally like to do is to understand a little bit more about why they're different. We still don't fully understand it. We don't understand how to predict that difference. The ultimate goal would be to have a very simple blood sample or very simple measurements from individuals that would help us then to predict or to tailor the advice on what is best suited to their metabolism.”

There is “huge interest” in such personalised nutrition and it is “definitely where the field is going”. But the whole area still needs “a lot more research and a lot more science before it could be rolled out”.


At the Cusp 


How can people eat the same food but metabolise it differently?

“We are really at the cusp of understanding this, but just to bring it back to basics: We eat our food, our digestion breaks down our food into our macromolecules and our body then has to metabolise those macromolecules to generate energy… What happens is that our metabolic pathways can be slightly different in different individuals.”

This can be due to either a genetic predisposition or our gut microbiota (microorganisms including bacteria, archaea and fungi that live in the digestive tracts) or our metabolic phenotype (the products of interactions among a variety of factors - dietary, other lifestyle/environmental, gut microbial and genetic)

“What we are trying to do is to harness those differences in metabolites and measure those differences in metabolites and use them to give more tailored recommendations to individuals.”

Other research groups are looking at those molecules to see if they are predictive of future risk of disease.

“There have been some interesting results that have found that harnessing the metabolism and the information you can get from metabolism can be very important and very predictive.”


Diet-related Disease


The most recent Global Burden of Disease report looked at the contributing factors in non-communicable diseases worldwide. These include Type 2 Diabetes, cardiovascular disease and certain cancers, such as colon cancer. 

“They associated 11 million deaths in 2017 to poor diet, meaning taking too much salt in and not enough whole grain, fruit and veg. Basically what they found was that diet was a key risk factor in these 11 million deaths in 2017.”



Nutritionists, dietitians and the HSE recommend a balanced diet. 

“You need to have a certain amount of animal protein and dairy protein to maintain some of that balance. For example, you need to have your vitamin B12 and you will get that in your diet from dairy products and from meat products.”

If people choose to be vegetarian or vegan “they have to be really careful and make sure that they are not becoming deficient in any of the key nutrients”.

For girls and teenagers, in particular, calcium “would be the key one”, along with iron. 

“They're really important in the early teenage years and for girls’ development and growth.”

People can still make “substantial changes” without going completely vegetarian or vegan.  

“A lot of people are choosing the option of flexitarian where you're reducing the amount of meat that you have in your diet, and you're supplementing and making sure that you get the protein from beans and pulses, nuts and legumes.”

Reducing the number of times you eat meat during the week will “make significant progress from a sustainability point of view”. 


Older Adults


A lot of work is underway in UCD to develop optimal products tailored towards older adults. B vitamins are particularly important for this cohort, so “quality of protein is really key” along with Omega-3 fats.




Interdisciplinarity is “fundamental” to Lorraine’s research. Her research team is “made up of very different people who have come from very different backgrounds with very different skill sets”. These include dietitians, nutritionists and chemists, among others. 

“I'm very fortunate to have strong collaborative links with colleagues in mathematics, engineering and medicine, so interdisciplinarity is really key for us. It's also a really fantastic opportunity to be working with individuals from different disciplines. You learn so much from it and their take on things can be quite different to our perspective of things.”


This article was brought to you by UCD Discovery - fuelling interdisciplinary collaborations. 



Professor Lorraine Brennan is a Full Professor of Human Nutrition in University College Dublin, Ireland.  Professor Brennan is at the forefront of nutrition and metabolomics research. Her research focuses on developing novel biomarker methods to assess dietary intake and for Precision Nutrition. Recent funding successes have included a European Research Council (ERC) Consolidator Award and US-Ireland tripartite grant. She is involved in a number of European consortia such as FoodBall and SusFood. 

Professor Brennan is Editor in Chief of Nutrition and Metabolism and Associate Editor for the American Journal of Clinical Nutrition. She has published over 180 research articles.  She has an active Public Engagement programme engaging with the local community in terms of Food and Nutrition.