Terms of Use
A short summary of how A Better Life may be used and what to expect from the tools.
General guidance, not medical advice
The tools and articles on this site are for general guidance only. They are not a substitute for professional medical, psychological, or clinical advice. If you have persistent sleep issues or other health concerns, please consult a qualified clinician.
No warranty
This service is provided as-is. While we try to base recommendations on commonly accepted sources, we do not guarantee the completeness, accuracy, or suitability of any output for a specific purpose.
Restricted use
Do not use the service in ways that place excessive load on the infrastructure, violate applicable laws, or infringe the rights of others.
References (Sources)
"References" on this site refers to the primary sources behind our recommendations — for example, around sleep duration or the 90-minute sleep cycle. We prioritize public institutions and well-established medical bodies, then peer-reviewed reviews, and only individual studies when necessary.
Main sources we rely on
• CDC / NIH — adult recommended sleep duration (7+ hours for adults, age-based ranges), and the CDC Yellow Book on jet lag disorder. • AASM (American Academy of Sleep Medicine) / SRS — age-based sleep duration guidelines and joint consensus statement on recommended sleep. • National Sleep Foundation (NSF) — recommended sleep range for adults (7–9 hours, ages 18–64). • Japan's Ministry of Health, Labour and Welfare — Sleep Guide for Health Promotion. • FORTH (Japan's MHLW Quarantine Information Office) — jet lag guidance for travelers. • Sleep Foundation — sleep cycles, sleep hygiene, light and sleep, morning light, jet lag, social jet lag, sleep debt, caffeine guidance, and "Is 6 Hours of Sleep Enough?". • Cleveland Clinic — sleep hygiene, 4-7-8 breathing, fatigue after full-night sleep, Familial Natural Short Sleep, and the best bedroom temperature for sleep. • World Health Organization (WHO) — Housing and health guidelines (recommended minimum indoor temperature). • Mayo Clinic — general sleep tips and sleep apnea information. • Harvard Health Publishing — resetting the circadian clock for jet lag. • NHS (UK) — insomnia self-help guidance. • NPR — reporting on wind-down routines and bedtime rituals. • U.S. Food and Drug Administration (FDA) — caffeine intake guidance. • European Food Safety Authority (EFSA) — caffeine safety assessment. • American College of Obstetricians and Gynecologists (ACOG) — caffeine during pregnancy and breastfeeding. • StatPearls (NIH National Library of Medicine) — caffeine withdrawal symptoms and timeline. • USDA FoodData Central / Japan's Standard Tables of Food Composition — caffeine values for common foods and drinks. • Drake C et al., Journal of Clinical Sleep Medicine 2013 — caffeine effects on sleep at 0, 3, and 6 hours before bedtime. • Vallat R, Walker MP et al., Nature Communications 2022 — how prior-night sleep, physical activity, and food intake relate to waking alertness. • Wittmann M, Roenneberg T et al., Chronobiology International 2006 — social jetlag and the misalignment of biological and social time. • Roenneberg T et al., Current Biology 2012 — social jetlag and its association with body weight. • Selected books and review papers (e.g., Walker, "Why We Sleep").
Updates
When we add new sources or change the evidence base behind a tool, we will update this page. See the rule documented in the project's CLAUDE.md.
Contact
Questions about these terms can be sent to [email protected].