Specialists in behavioural AI for health, safety, and real-world use
We support teams to design and evaluate AI systems that influence human behaviour, ensuring they are evidence-informed, safe, and appropriate for real-world contexts.
Meet The Core Team
Dr Paul Sacher
Founder, Lead Digital Health Clinician & Behavioural AI Scientist. Senior Lecturer (hon) at Imperial College and Co-Founder Behavioural AI Institute
Chris Reynolds
Chief Growth Officer and Senior Commercial Advisor. Has delivered exceptional growth in both SME and larger ventures
Dr Emmie Fulton
Lead Psychologist & Behavioural Scientist. CBT & science-based tools for mental well-being. Phd in Health Psychology
Gabriele Medeot
Machine Learning Researcher & AI System Architect. MSc in Artificial Intelligence
Jorge Alexander
AI & Digital Health Advisor. Entrepreneur and Co-founder of Syndi Health and others. MSc in Artificial Intelligence (Imperial).
Lev Perlman
FractionalChief Technology Officer. Senior Technical and Architecture Advisor. Prolific B2B and SaaS founder, and Mentor at Google for Startups. Founder of Metamindz
Sacher AI was founded in 2024 to address a growing gap between AI innovation and real-world safety, effectiveness, and use. Our team brings together expertise across science, engineering, and clinical practice to support organisations designing AI systems that interact directly with people.
Our purpose is to shape how human–AI systems are designed and evaluated — ensuring they are trustworthy, evidence-informed, and fit for real-world use in health and other high-stakes domains. Alongside client work, we develop internal tools and evaluation approaches to surface behavioural and safety risks.
Our work is grounded in academic and clinical rigour through our partnership with the Behavioural AI Institute and an honorary senior lectureship at Imperial College London — bringing research-grade standards to applied AI development and evaluation.
Dr Paul Sacher is a digital health clinician and behavioural AI scientist with over 25 years of experience designing, evaluating, and scaling large-scale health behaviour programmes and human-facing AI systems.
As founder and CEO of Sacher AI, and co-founder of the Behavioural AI Institute , Paul leads work at the intersection of behavioural science, clinical insight, and AI safety. His focus is on how AI systems interact with people in real-world settings, and how behavioural and clinical risks can be identified and addressed during development and deployment. This includes leading the development of PromptSafe, a platform designed to support structured evaluation of risk and alignment in patient-facing AI systems.
Paul has contributed to the design and evaluation of large-scale conversational AI systems used in medication and device-supported weight management, and led the development of a peer-reviewed evaluation framework for generative AI in health, now applied internationally. Previously, he co-founded and scaled MEND, a family-based obesity programme that supported more than 130,000 families worldwide, evaluated through multiple randomised controlled trials and recognised by the CDC and the American Academy of Pediatrics. He has authored over 27 peer-reviewed publications and presented at 49 international conferences.
- Key strategic, clinical, and scientific lead for Allurion's Generative AI Conversational Agent — a patient-facing AI health coach for patients receiving GLP-1s, bariatric surgery, intragastric balloons, and lifestyle programmes, designed to augment provider care and deployed across 80 clinics in 22 countries. Supported patients receiving GLP-1 medications, intragastric balloons, and bariatric surgery — medication and device-supported care at scale.
- Designed and led the transformation of Slimming World's UK, Ireland, and USA digital patient platform — built from the ground up for scalability and global adaptability, managing budgets exceeding $6.1m per year. The platform had over 1 million active members on departure.
- Led the multidisciplinary product development and international programme adaptation team responsible for building the largest suite of digitally supported family-based weight management programmes and services, delivered to children and adults in 7 countries (UK, USA, Denmark, Australia, Canada, Netherlands, and New Zealand) — recommended by the CDC and American Academy of Pediatrics.
- Directed all stages of development of a health-span and longevity precision medicine start-up, from inception through to pilot.
- Over 27 years of healthcare and academic experience working in clinical and research roles, leading research and evaluation strategies that resulted in collaborations with 16 prestigious academic institutions across 6 countries — producing 36 peer-reviewed scientific articles, including 4 randomised controlled trials.
- Led Slimming World's digital research agenda and strategy, resulting in participation in a €5m, multi-country EU trial focused on development of mHealth technologies to support long-term behaviour change — selected by 13 research institutions as Exploitation and Impact Leader.
- Led research of a digital behaviour change coaching intervention and novel AI conversational agent, resulting in scientific publications featured in multiple company press releases.
- Designed and contributed to qualitative evaluations providing deep understanding of people from multicultural and diverse communities across the UK, USA, Australia, and Canada.
- Commissioned by Morgan Stanley International Foundation to conduct a multicultural community engagement and user needs project to guide implementation of their global Healthy Cities initiative.
- Generated and managed the largest child weight management dissemination dataset internationally; established and chaired 3 international Scientific and Medical Advisory Boards.
- Appointed by the board of Allurion Technologies (NYSE-listed) to create and lead the Behavioural Science team — leading a team of multidisciplinary experts and global Key Opinion Leaders as the organisation-wide Behavioural Science subject matter expert.
- Co-founder of MEND (Mind, Exercise, Nutrition…Do it!) — the largest and most effective provider of family-based child weight management services. Grew MEND from a UCL University spin-out to a multi-million dollar per year revenue company with a team of 60 employees across 3 countries (USA, UK, and Australia).
- Successfully appointed by Slimming World's board for a newly created role to spearhead the digital adaptation of the UK's largest adult weight management organisation — directing all stages of development of their global digital strategy and USA ecommerce subscription service launch, growing to over 1 million members.
- Following the USA launches of MEND and Slimming World, developed and led a comprehensive targeted external affairs strategy — taking previously unknown UK programmes to become well-respected providers in the competitive USA weight management market.
- Initiated the industry's first strategic partnership with the Academy of Nutrition and Dietetics (100,000 members) to co-develop a reimbursable patient referral and feedback process.
- Key team member at Allurion Technologies pre-IPO on the New York Stock Exchange.
- Commissioned by US public agencies including the Centers for Disease Control and Prevention and the National Association of Community Health Centers; worked with Blue Cross Blue Shield entities, Wellpoint, Kaiser Permanente, and AmeriGroup to fund and scale childhood obesity programmes.
- Grew MEND revenue to $6.4m per annum via grants, partnerships, and funding awards.
- Led and/or contributed to 8 funding body research grants resulting in $12m of research funding.
- Invited speaker at 49 national and international conferences, including twice at the International Congress of Obesity, the World Diabetes Congress, the British Medical Association's 175th anniversary conference, the Royal Society of Medicine, and Oxford University.
- TV: Health expert for Jamie Oliver's Return to School Dinners. Co-presenter and expert across 4 series of BBC's Honey We're Killing the Kids — plus 60+ appearances on BBC, Sky, Channel 4, and ITV.
- Press: 150+ interviews and quotes in national papers and magazines, including Time Magazine. Radio: 80+ interviews for national and regional radio stations.
- Books: Authored From Kid to Superkid (Vermilion) and co-authored 2 books with the UK's bestselling child health and wellbeing authors (Annabel Karmel, Gina Ford).
- Invited to provide oral evidence at the UK House of Lords Behaviour Change Enquiry and the Academy of Royal Medical Colleges obesity review.
- Awards: MEND selected as the only scalable programme in the CDC Childhood Obesity Research Demonstration Project. British Dietetic Association's most prestigious award, 2011.
Behaviourally informed AI, designed for safe and responsible real-world use.
