Behaviour · Limited evidence
Adaptive support at the right moment
Context-tailored digital interventions can be feasible and helpful, but their effect varies and must be measured per person and per decision.
Systematic and scoping reviews · 2 sources · 2 min
What the studies show
- Just-in-time interventions were feasible and well-accepted in most studies.
- The effect on physical activity was small and heterogeneous.
- Excessive notifications reduce engagement.
How Letz applies it
Letz enforces a daily notification cap and presents a single coach decision at a time; each prompt logs whether it prompted action.
Who it applies to
Mobile apps for physical activity, diet, and behavior change in adults.
Limits
Messages can increase app usage without necessarily changing behavior; frequency and user annoyance must be managed.
Sources
- Hardeman et al., International Journal of Behavioral Nutrition and Physical Activity, 2019 DOI 10.1186/s12966-019-0792-7
- Hsu et al., British Journal of Health Psychology, 2025 DOI 10.1111/bjhp.12766
More in Behaviour
- Digital Personalization and BehaviorPersonalized mobile interventions show potential benefits for health behaviors, although outcomes vary across programs.
- Tracking is the most effective techniqueSelf-monitoring of diet, weight, and activity is consistently associated with greater weight loss; the behavior change technique taxonomy ranks it among the most effective.
- Building a workout habitIn new gym members, working out at least four times per week for six weeks was the minimum threshold to form a habit; consistency and simplicity predicted habit formation.