About

Built on science, not willpower

Key to Health was founded by physicians who believed weight management deserved better evidence.

Key to Health breath sensor

Over 70% of U.S. adults are overweight or have obesity. The programs that produce durable results tend to require expensive infrastructure — physicians, coaches, or indefinite medication. The programs that scale tend to lack clinical evidence. We started Key to Health to close that gap.

The science of breath acetone as a biomarker of fat metabolism has been published since the 1960s. What changed is the technology to measure it practically — in a handheld device connected to a smartphone — and our commitment to proving it works through the same standards used to evaluate pharmaceuticals: randomized controlled trials, independent oversight, and peer-reviewed publication.

Team

Founded by physicians and engineers

Ray Wu, MD

Co-founder & CEO

Ray graduated from Weill Cornell Medical College and has published peer-reviewed research in the molecular biology of diabetes and metabolism. He leads Key to Health's product development, clinical research program, and regulatory strategy.

Liane Nakamura

Co-founder

Liane is an experienced engineer and product developer who leads Key to Health's hardware and software development, including the Generation 2 breath sensor and the KEY AI agent.

Milestones

What we've proven so far

2018
Key to Health founded
2021
RCT published in Obesity — ~10% weight loss, 2.2× vs. comparator
2022
Mediation analysis published in JMIR mHealth — mechanism evidence
2025
1-year RCT follow-up published in Obesity Science & Practice
2026
Real-world evidence study (N=11,365, 2-year outcomes) submitted for peer review
Weight change across 48 weeks — Key to Health vs. comparator

What we believe

These principles shape how we build the product and present our evidence.

Our commitments

  • Prove it works through gold-standard research — not testimonials
  • Present evidence honestly, including limitations
  • Build technology that scales without requiring expensive human infrastructure
  • Align with established dietary science, not fad diets
  • Never claim to treat, cure, or prevent any disease

What we won't do

  • Cite studies we haven't verified
  • Guarantee individual results
  • Make claims that outrun our evidence
  • Hide behind vague language like "clinically tested" without specifics

See our evidence

Four published or submitted studies — presented with strengths and limitations.

Clinical evidence