Dr. Laz Ranasinghe is a leading NHS Doctor, personal trainer and nutrition coach who works at the intersection of clinical medicine and public health communication. With a career spanning hands-on medical practice to founding charities that work at the heart of those in need, he has witnessed firsthand the scale of diet-related diseases, leading him to ask the question: why, despite constant dietary advice, are so many people gaining weight so rapidly? Drawing together evolutionary biology, human physiology and the economics of the modern food industry into a single, connected argument, he works to reframe the obesity and diet-related disease crisis as a systemic, environmental failure.
While studying at Imperial College London to gain his MBBS BSC (Hons), his curiosity about medicine grew as he spent three weeks at the Guangzhou Institute of Respiratory Medicine as an Undergraduate Researcher, where he assisted with a study on the use of carbon dioxide in measuring the maximum inspiratory pressure. After gaining 25 prizes for academic excellence and being consistently ranked among the top of his cohort, Laz graduated in 2020 and became the Lead Editor of the world's first AI-powered dementia screening app, Mindstep, working to edit a crucial social media campaign. The same year, his NHS career began as an FiY1 Doctor at London North West Healthcare NHS Trust. Consistently working to build his professional knowledge, he completed rotations in Elderly Medicine, General Surgery and Infectious Diseases as an Academic Foundation Doctor.
In 2023, Laz began further development as an ACCS Anaesthetics Trainee CT1-2 at Homerton Healthcare NHS Foundation Trust. He then completed his ACCS Anaesthetics CT3 training at Barts Health NHS Trust in 2025, which led to his current position as an ACCS Anaesthetics CT4 at Barking, Havering and Redbridge University Hospital NHS Trust. In addition to his medical work, Laz is a passionate advocate for those in need through his charity foundations. In 2010, he founded Smile with the aim of collecting donations to help support orphaned and disadvantaged children in Sri Lanka. Additionally, Laz founded Make a Medic in 2020, where he developed medical education and public health initiatives in low- and middle-income countries.
Laz always strives to develop his understanding, which has been widely acknowledged throughout his career, with recognition including the Third Sector Rising Star Award 2023, being ranked in the top 1% globally in the MRCP (UK) and gaining the Nuffield Medal for the highest overall mark in the Primary FRCA in 2025. Laz now shares his expertise through his talks, such as his flagship keynote, Beyond Calories, where he challenges the conventional calorie-counting model to explore how human appetite regulation actually works and how the modern food environment has learned to exploit it. Regularly developing new material to explore the science of satiety, evolutionary biology and preventive medicine, he is regularly hired to speak at NHS Trusts, public events and international conferences as a sought-after public speaker.
Dr. Laz Ranasinghe's official speaking topics are listed below:
- Beyond calories: why the conventional calorie model fails us, and what actually drives appetite and weight
- The science of satiety: how fullness mechanisms evolved, and how the modern food industry works against them
- Ultraprocessed food and the modern food environment
- Behaviour change beyond willpower, why diets fail and what actually works
Official Testimonials From In-Person & Virtual Events
"Dr Lasith Ranasinghe is a fantastic speaker. I attended one of his talks in London and enjoyed it so much that I invited him to speak to my online wellness community, Heal Thru Food. He has a real gift for taking complex concepts and explaining them in a way that is clear, engaging, and genuinely useful. His talk sparked thoughtful discussion among our members and left everyone feeling both inspired and better informed." - Trinity, HealThruFood
"Thank you so much for coming to give your talk 'Beyond Calories' at the North Middlesex Hospital Foundation Enhance programme. We had great attendance with around 30 FY1 and FY2 doctors at each of the sessions on 9th March and 11th March 2026. This was a really helpful talk for understanding nutrition based on the latest knowledge and fitted well with the Foundation Enhance programme curriculum, in particular the theme of wellbeing and the person centred care domain. You also presented the information in a way that gave tips for the Foundation Doctors to practice this in real life and how to approach this with patients. This was obviously a topic they were interested in because some of them talked about their own experience in the Q&A, and had lots of questions for you. I really appreciate you participating in our programme and hope we can work together again in the future." - Dr Alice, North Middlesex Hospital
"Dr Ranasinghe delivered an outstanding and highly engaging session, 'Beyond Calories: Navigating an Ultra-Processed World,' as part of our IMT Half Day Teaching Programme at Guy's and St Thomas' NHS Foundation Trust. His session was exceptionally well received, with trainees consistently highlighting its relevance, practicality, and thought-provoking nature. Trainees particularly valued his ability to challenge common misconceptions around calorie counting and weight loss, and to clearly explain the wider drivers of obesity in a way that was both evidence-based and highly relevant to everyday clinical practice. The session was especially praised for its practicality. Attendees highlighted how useful it was to gain clear frameworks for discussing diet with patients, alongside actionable advice that could be immediately applied in clinical settings. His explanations of ultra-processed foods and how to identify and reduce them were described as eye-opening and directly applicable to both personal and professional contexts. What set Dr Ranasinghe apart was his ability to make a complex and often overlooked topic accessible, engaging, and genuinely thought-provoking. Many trainees reflected that the session prompted them to rethink not only how they approach conversations about nutrition with patients, but also their own lifestyle choices. We would highly recommend Dr Ranasinghe as a speaker for any medical education programme. His teaching is clear, practical, and deeply relevant to modern healthcare." - Dr Anushka, GSTT IMT
- 2026 - ACCS Anaesthetics CT4 at Barking, Havering and Redbridge University Hospitals NHS Trust
- 2025 - Awarded the Nuffield Medal for achieving the highest overall mark in the Primary FRCA
- 2025 - ACCS Anaesthetics CT3 at Barts Health NHS Trust
- 2024 - Ranked in the top 1% globally in the MRCP (UK)
- 2023 - Recipient of the Third Sector Rising Star Award
- 2023 - ACCS Anaesthetics Trainee at Homerton Healthcare NHS Foundation Trust
- 2021 - Academic Foundation Doctor at Imperial College Healthcare NHS Trust
- 2020 - Academic Foundation Doctor at London North West University Healthcare NHS Trust
- 2020 - FiY1 Doctor at London North West University Healthcare NHS Trust
- 2020 - Graduated from Imperial College London with an MBBS and first-class BSc (Hons), receiving 25 prizes for academic excellence and consistently ranking among the top of the cohort
- 2020 - Lead Editor at Mindstep, the world’s first AI-powered dementia screening app, leading a social media campaign
- 2020 - Founded Make a Medic, a registered charity supporting medical education and public health initiatives in low and middle-income countries
- 2017 - Undergraduate Researcher at the Guangzhou Institute of Respiratory Medicine, supporting a study into the use of carbon monoxide to measure maximal inspiratory pressure
- 2010 - Founded Smile to collect donations for orphaned and disadvantaged children in Sri Lanka
How to hire Dr. Laz Ranasinghe
Contact the Champions Speakers Agency to provisionally enquire about hiring Dr. Laz Ranasinghe for your next event, today. To get in touch, simply call an official booking agent on 0207 1010 553 or email us at [email protected] for more information.
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