Evidence map›Paper›PMID 40813712›Full record

ArticleNature medicine2025

A personal health large language model for sleep and fitness coaching.

Justin Khasentino, Anastasiya Belyaeva, Xin Liu, Zhun Yang, Nicholas A Furlotte, Chace Lee, Erik Schenck, Yojan Patel, Jian Cui, Logan Douglas Schneider and 24 more

Abstract read
In one paragraph

Article in Nature medicine, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
18citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

18 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Article
  3. Ethical Considerations in Personal Health Large Language Models.Journal of medical Internet research · 2026
    Article
  4. Article
  5. Article
  6. Review
  7. Article
  8. Article
  9. Review
  10. Article
  11. State of clinical AI in 2026.BMJ digital health & AI · 2026
    Review
  12. Review
  13. Article
  14. Article
  15. Article
  16. Article
  17. Article
  18. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

34 authors.

Justin Khasentino *Google Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0003-1012-9556
Anastasiya Belyaeva *Google Research, Mountain View, CA, USA. belyaeva@google.com.ORCID http://orcid.org/0009-0008-8275-4047
Xin Liu *Google Research, Mountain View, CA, USA. xliucs@google.com.ORCID http://orcid.org/0000-0002-9279-5386
Zhun Yang *Google Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0002-9043-5774
Nicholas A Furlotte *Google Research, Mountain View, CA, USA.
Chace LeeGoogle Research, Mountain View, CA, USA.
Erik SchenckGoogle Research, Mountain View, CA, USA.
Yojan PatelGoogle Research, Mountain View, CA, USA.
Jian CuiGoogle Research, Mountain View, CA, USA.
Logan Douglas SchneiderGoogle Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0001-8729-5224
Robby BryantGoogle Research, Mountain View, CA, USA.
Ryan G GomesGoogle Research, Mountain View, CA, USA.
Allen JiangGoogle Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0003-2809-0469
Roy LeeGoogle Research, Mountain View, CA, USA.
Yun LiuGoogle Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0003-4079-8275
Javier PerezGoogle Research, Mountain View, CA, USA.ORCID http://orcid.org/0009-0009-4510-3074
Jameson K RogersGoogle Research, Mountain View, CA, USA.
Cathy SpeedGoogle Research, Mountain View, CA, USA.
Shyam TailorGoogle Research, Mountain View, CA, USA.
Megan WalkerGoogle Research, Mountain View, CA, USA.
Jeffrey YuGoogle Research, Mountain View, CA, USA.
Tim AlthoffGoogle Research, Mountain View, CA, USA.
Conor HeneghanGoogle Research, Mountain View, CA, USA.
John HernandezGoogle Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0002-3313-430X
Mark MalhotraGoogle Research, Mountain View, CA, USA.
Leor SternGoogle Research, Mountain View, CA, USA.
Yossi MatiasGoogle Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0003-3960-6002
Greg S CorradoGoogle Research, Mountain View, CA, USA.
Shwetak PatelGoogle Research, Mountain View, CA, USA.
Shravya ShettyGoogle Research, Mountain View, CA, USA.ORCID http://orcid.org/0000-0003-3783-3172
Jiening ZhanGoogle Research, Mountain View, CA, USA.
Shruthi PrabhakaraGoogle Research, Mountain View, CA, USA.
Daniel McDuffGoogle Research, Mountain View, CA, USA. dmcduff@google.com.ORCID http://orcid.org/0000-0001-7313-0082
Cory Y McLeanGoogle Research, Mountain View, CA, USA. cym@google.com.ORCID http://orcid.org/0000-0001-9928-8216

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Although large language models (LLMs) show promise for clinical healthcare applications, their utility for personalized health monitoring using wearable device data remains underexplored. Here we introduce the Personal Health Large Language Model (PH-LLM), designed for applications in sleep and fitness. PH-LLM is a version of the Gemini LLM that was finetuned for text understanding and reasoning when applied to aggregated daily-resolution numerical sensor data. We created three benchmark datasets to assess multiple complementary aspects of sleep and fitness: expert domain knowledge, generation of personalized insights and recommendations and prediction of self-reported sleep quality from longitudinal data. PH-LLM achieved scores that exceeded a sample of human experts on multiple-choice examinations in sleep medicine (79% versus 76%) and fitness (88% versus 71%). In a comprehensive evaluation involving 857 real-world case studies, PH-LLM performed similarly to human experts for fitness-related tasks and improved over the base Gemini model in providing personalized sleep insights. Finally, PH-LLM effectively predicted self-reported sleep quality using a multimodal encoding of wearable sensor data, further demonstrating its ability to effectively contextualize wearable modalities. This work highlights the potential of LLMs to revolutionize personal health monitoring via tailored insights and predictions from wearable data and provides datasets, rubrics and benchmark performance to further accelerate personal health-related LLM research.

Indexed as

LanguageMentoringPhysical FitnessSleepAdultFemaleHumansLarge Language ModelsMaleMiddle AgedPrecision MedicineSelf ReportSleep QualityWearable Electronic Devices

Identifiers

PMID40813712
PMCPMC12532688

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.