Why thirst fades
In a 1984 study, healthy older and younger men went 24 hours without water. Although the older men were just as short of water, they felt less thirsty, and when allowed to drink they did not fully make up the deficit. Public health heat guidance also notes that older adults sweat and regulate body temperature less well.
Reference intakes barely drop with age. EFSA uses the same adequate intakes for older adults as for younger adults (2.0 L total water for women, 2.5 L for men, food included). Korea’s 2025 reference intakes, as one example, set fluids at about 0.9–1.1 L a day for people 65 and over, with water from food counted separately.
Check these first
- Fluid restrictions — some heart and kidney conditions come with a limit on fluids. In that case do not push more water; follow the amount the doctor set.
- Medications — if they take diuretics or other fluid-related medicines, agree on amounts with their doctor or pharmacist.
- Night-time bathroom trips — many older people avoid drinking to avoid waking at night. Shift drinking to the daytime and taper off in the evening.
Low-pressure ways to help
- Attach a glass to things they already do: each meal, each time they take their pills.
- If they dislike plain water, familiar teas count as fluids too (drink by drink).
- A glass or bottle of known size makes "how many today?" an easy question.
- Call on hot days (heat waves).
Setting up their phone
The Android app "Water Tracker" keeps data only on the phone it is installed on, so install it on your parent’s phone.
A modest goal, daytime-only reminders
In Water Tracker settings, start the daily target low with the minus and plus buttons (or at the amount their doctor gave), and set reminder start and end times from after breakfast to around dinner. No night reminders means less resistance.
Just one button: "Log a glass"
Tapping "Log a glass" on the notification records 200 ml of water, applied when the app is next opened. Even if the app itself feels unfamiliar, this one button is all they need.
Get the day as an image
The share button at the top right of the Today tab makes a card with the day’s intake to send by messenger. Asking for one each evening doubles as a check-in.
FAQ
Can I see their log on my phone?
The app sends no data to a server, so there is no live view from another phone. You can receive share cards or the CSV export from Settings.
They eat a lot of fruit instead of drinking.
Water in fruit and soup counts toward total water. With a medical condition, though, sugar or potassium in fruit can matter, so check with their doctor.
Sources: Phillips et al., N Engl J Med 1984 (reduced thirst in older men) · EFSA, Dietary Reference Values for water (2010) · Korean Nutrition Society, 2025 Dietary Reference Intakes for Koreans · CDC NIOSH, Heat Stress: Hydration
Water Tracker: Drink Reminder
No sign-up, and your drink log stays on your phone. Free on Android.