A systematic review of artificial intelligence chatbots for promoting physical activity, healthy diet, and weight loss

Int J Behav Nutr Phys Act. 2021 Dec 11;18(1):160. doi: 10.1186/s12966-021-01224-6.


Background: This systematic review aimed to evaluate AI chatbot characteristics, functions, and core conversational capacities and investigate whether AI chatbot interventions were effective in changing physical activity, healthy eating, weight management behaviors, and other related health outcomes.

Methods: In collaboration with a medical librarian, six electronic bibliographic databases (PubMed, EMBASE, ACM Digital Library, Web of Science, PsycINFO, and IEEE) were searched to identify relevant studies. Only randomized controlled trials or quasi-experimental studies were included. Studies were screened by two independent reviewers, and any discrepancy was resolved by a third reviewer. The National Institutes of Health quality assessment tools were used to assess risk of bias in individual studies. We applied the AI Chatbot Behavior Change Model to characterize components of chatbot interventions, including chatbot characteristics, persuasive and relational capacity, and evaluation of outcomes.

Results: The database search retrieved 1692 citations, and 9 studies met the inclusion criteria. Of the 9 studies, 4 were randomized controlled trials and 5 were quasi-experimental studies. Five out of the seven studies suggest chatbot interventions are promising strategies in increasing physical activity. In contrast, the number of studies focusing on changing diet and weight status was limited. Outcome assessments, however, were reported inconsistently across the studies. Eighty-nine and thirty-three percent of the studies specified a name and gender (i.e., woman) of the chatbot, respectively. Over half (56%) of the studies used a constrained chatbot (i.e., rule-based), while the remaining studies used unconstrained chatbots that resemble human-to-human communication.

Conclusion: Chatbots may improve physical activity, but we were not able to make definitive conclusions regarding the efficacy of chatbot interventions on physical activity, diet, and weight management/loss. Application of AI chatbots is an emerging field of research in lifestyle modification programs and is expected to grow exponentially. Thus, standardization of designing and reporting chatbot interventions is warranted in the near future.

Systematic review registration: International Prospective Register of Systematic Reviews (PROSPERO): CRD42020216761 .

Keywords: Artificial intelligence; Chatbot; Conversational agent; Diet; Nutrition; Physical activity; Sedentary behavior; Systematic review; Weight loss; Weight maintenance.

Publication types

  • Research Support, N.I.H., Extramural
  • Review
  • Systematic Review

MeSH terms

  • Artificial Intelligence*
  • Diet, Healthy*
  • Exercise
  • Female
  • Humans
  • Weight Loss