Researchers Unplugged: Meet the Researcher Studying How the Timing of Our Meals Shapes Health
Mass General Brigham is home to a research community of thousands of individuals working to understand disease and develop solutions to medicine’s most pressing challenges.
But who are they? And what do they do when they’re not conducting research? Learn more about them in the Researchers Unplugged series!
From clinical research coordinators to postdoctoral fellows, research technicians, graduate students and principal investigators—they are all part of research at Mass General Brigham.
Our next guest in the series is Ioannis Lempesis MD, PhD
1. What lab do you work in and what is your role?
I am a postdoctoral research fellow in the Medical Chronobiology Program, within the Division of Sleep Medicine at Brigham and Women's Hospital.
I study how our body's internal clocks influence the way we process food, and how changing the timing and composition of meals might help prevent or treat diseases like obesity and diabetes.
Ioannis Lempesis, MD, PhD
Before moving to Boston and joining Mass General Brigham, I studied medicine in Greece and completed part of my internal medicine training in Athens.
I then pursued a joint PhD between the University of Birmingham in the United Kingdom (UK) and Maastricht University in the Netherlands, where I investigated how fat tissue functions in obesity and contributes to metabolic disease.
Looking back, every stage of my journey, from Greece to the UK, the Netherlands and now Boston, has been driven by the same curiosity: Understanding how the human body adapts to its environment, and how that knowledge can improve patients' lives.
2. Can you explain your research in layperson's terms?
I like to think of our bodies as having a master clock and lots of tiny clocks that help tell different organs what time it is and what they should be doing.
We study how not only what we eat, but also when we eat, affects things such as blood sugar, hunger, how many calories we burn and how our bodies use energy throughout the day.
Ioannis and his PI, Frank Scheer, PhD
We also investigate what happens when people stay awake much later than usual, like during night shifts, and whether this changes how the body works.
By understanding these patterns, we hope to find better ways to improve health.
3. When and why did you get interested in this work?
I've been fascinated by science for as long as I can remember. Although neither of my parents works in healthcare nor attended university, they always encouraged my curiosity.
I knew from an early age that I wanted to become a doctor, originally inspired by my childhood pediatrician. During medical school I found myself drawn to endocrinology because it connects so many different systems in the body and bridges basic science with patient care.
I've always been fascinated by time. Long before I studied circadian rhythms, I found myself drawn to writers like T. S. Eliot and Jorge Luis Borges, who explore memory and time. It still amazes me that biology has its own language of time, and that understanding those internal clocks might improve people's health.
My current research combines many of the things that have always interested me: Human physiology, metabolism, behavior and chronobiology.
Beyond science, I've also long been fascinated by the concept of time itself, both philosophically and in literature, so studying the biology of time feels like a natural fit.
4. What do you do outside of the lab?
If you can't find me in the hospital or the lab, there's a good chance I'm browsing a second-hand bookshop (rarely leaving empty-handed), sitting in a café with a book or watching a film at the cinema.
I have always loved the arts in almost every form: Literature, poetry, cinema, painting, music. I also enjoy photography, painting, and writing essays and poetry. And, of course, I enjoy spending time with friends and discovering new cuisines around Boston.
Some of Ioannis' paintings inspired by his PhD studies and campus of the University of Birmingham, UK
5. What is your favorite TV show, podcast, book or movie?
One of my favourite TV series is Twin Peaks, especially Twin Peaks: The Return. I love its dreamlike atmosphere and unconventional sense of time, which probably says something about my research interests!
Among filmmakers, David Lynch, Andrei Tarkovsky, Ingmar Bergman and Yorgos Lanthimos have had a great influence on me.
A recent favourite book is Near to the Wild Heart by Clarice Lispector, while lifelong favourites include works of Jorge Luis Borges, Greek poets like Kiki Dimoula, George Seferis and Odysseas Elytis, T. S. Eliot, particularly Four Quartets, a poem that beautifully reflects on time, and Patti Smith (both her books and music, especially Horses).
6. What's a fun fact about yourself?
I speak three languages, can understand several more, and I'm always looking for an excuse to learn another.
7. What do you like most about conducting research at Mass General Brigham?
Mass General Brigham brings together researchers from many different disciplines, countries and backgrounds who all share the same goal of improving patient care. Working in such an environment means you're constantly learning something new not only from your own field but from colleagues with completely different perspectives.
It also reminds me of the importance of working in a team, as the best science is never done alone.
8. If you had to compare your Principal Investigator to a fictional character, who would it be?
I would compare my PI, Prof Frank Scheer, to Gandalf. He's incredibly knowledgeable and experienced, but he's also deeply involved in day-to-day science and enjoys exploring new questions alongside his trainees.
Like Gandalf, he guides people while encouraging them to find their own path.
9. If you could only eat one dish for the rest of your life, what would it be?
That's an almost impossible question!
I love Mediterranean food, especially Greek and Italian cuisine, but if I had to choose just one dish, it would probably be either moussaka or a classic Neapolitan Margherita pizza.
10. What's your favorite way to spend your Sunday?
Coffee. Books. Exploration.
If I'm not in the lab admitting or discharging study participants, my ideal Sunday starts with a good coffee and a book, followed by wandering somewhere new, whether that's a neighborhood in Boston or a nearby town reached by commuter rail.
It's Your Turn to Shine!
Do you work in research at Mass General Brigham? Are you willing to provide short written answers to 10-ish fun questions about you and your science? Then you (yes, you) could be the next star of Researchers Unplugged.