Healthy habits that stick, and how to build them
The healthy habits UK health advice recommends, and what research shows about making a new one stick, from how long it takes to what to do when you miss a day.
- Written by
- Elaine B.
- Last updated
- Reading time
- 8 min read
Overview
Healthy habits are good-for-you actions you do almost automatically, such as a daily walk or eating 5 portions of fruit and veg. To make one stick, start small, tie it to something you already do and repeat it at the same time each day. Expect about two months or more, not 21 days.
Key points
- UK advice is to move every day, eat 5 a day, drink 6 to 8 glasses and keep regular sleep times.
- New habits took 66 days on average to feel automatic in a UCL study, and often longer.
- The 21-day figure came from plastic surgery patients, not from habit research.
- Start with one small action, tied to your routine, at the same time and place each day.
- Missing the odd day didn't seriously set people back.
What are healthy habits?
Healthy habits are good-for-you things you do almost without thinking, because the same moment in your day sets them off each time [1]. A walk after lunch is one. So is a glass of water with breakfast.
Once a habit has formed, it keeps going with little effort or willpower. That's why it pays to build the right ones on purpose, and to know how long it really takes.
Plenty of us have started something new on a Monday and quietly dropped it by Thursday. That's rarely a lack of willpower. More often the habit was never tied to a moment in the day.
8 healthy habits worth starting
UK health advice comes down to a short list. Each of these is something you can do every day or every week.
| Habit | What UK advice says |
|---|---|
| Move every day | Be active daily, building up to at least 150 minutes of moderate activity a week, such as brisk walking [2] |
| Build strength | Muscle-strengthening activity on at least 2 days a week [2] |
| Sit less | Break up long spells of sitting with some light activity [2] |
| Eat 5 a day | At least 5 portions of a variety of fruit and vegetables a day [3] |
| Drink enough | 6 to 8 cups or glasses of fluid a day. Water, lower-fat milk, tea and coffee all count [3] |
| Eat oily fish | At least 2 portions of fish a week, 1 of them oily, such as salmon or sardines [3] |
| Keep regular sleep times | Go to bed and get up at the same time every day [4] |
| Have caffeine earlier | Its effects can last up to 7 hours, so avoid it in the evening if you sleep badly [4] |
If you're 65 or over, the advice is to be active every day and to add activities that help strength, balance and flexibility on 2 days a week [2]. Any activity is better than none.
You don't need all eight at once. The rest of this guide is about picking one and making it last.
How long does a habit take to form?
About two months on average, and often longer. In a study at UCL, volunteers each picked one healthy action, such as drinking a glass of water with a meal, and did it every day. It took an average of 66 days to become automatic [1].
The spread was wide. The fastest took 18 days, while the slowest was still getting there when the 12-week study ended and was estimated to need 254 [5].
A 2024 review of 20 studies, with 2,601 people, advises expecting two to five months for a new health habit to feel automatic Early [5]. The studies were small and varied, so treat any single number as a rough guide.
Where does 21 days come from?
Not from habit research. It traces back to the self-help book Psycho-Cybernetics and to plastic surgery patients, who took about three weeks to get used to their new faces [1][5]. The review's results "clearly refute" the idea that habits form in about 21 days [5].
How to make a healthy habit stick
Habits form when you repeat the same action in the same situation until it happens without effort [1]. Across studies, plans built this way made new habits stronger Moderate [5]. These six steps come from that research.
- Start small. Simple actions, such as drinking a glass of water, became automatic sooner than bigger routines such as 50 sit-ups [1]. Getting off the bus a stop or two early is a better start than walking the whole way [1].
- Tie it to something you already do. A moment in your daily routine, such as "when I go on my lunch break", gives the habit a steady trigger [1]. Write it down as a plan, for example "after I have lunch, I'll have a piece of fruit".
- Keep the same time and place. People who did their habit in a consistent setting built stronger habits, and the early repeats counted for the most [5].
- Add something rather than ban something. You can't form a habit of not doing something, so pick a new action to do instead, such as eating an apple rather than "no crisps" [1].
- Choose something you'll enjoy. The UK's chief medical officers say lasting change is most likely when an activity is enjoyable, useful or part of your everyday routine [2].
- Tick it off for 10 weeks. UCL's habit sheet for GP patients is a 10-week tick chart, and it says that by the end you should find you're doing the action without thinking [1].
What if you miss a day?
Carry on. In the UCL study, missing the odd day didn't seriously set people back, and the habit picked up again after one missed day [1].
Think of a missed day as a wobble, not a fall. What matters is getting back to it the next day. If a holiday or a busy week breaks your routine, go back to the same trigger as soon as you can.
What does a healthy daily routine look like?
It's one built from small, regular anchors. The NHS suggests these to keep your energy up through the day [4].
- Get up and go to bed at the same times every day, and avoid naps.
- Eat regular meals and healthy snacks every 3 to 4 hours, rather than a large meal less often.
- Take a walk. Even a single 15-minute walk can give you an energy boost.
- Drink enough, because mild dehydration can make you feel tired.
- Have your last coffee well before the evening.
Mornings may be a good place to start. In the review, habits done in the morning tended to be stronger, though the evidence for this is thin [5]. Our guides to falling asleep fast and brain fog cover two of the most common reasons people start a new routine.
Frequently asked questions
What are 10 healthy habits?
Ten good ones are moving every day, strength work twice a week, sitting less, eating 5 a day, drinking 6 to 8 glasses of fluid, eating oily fish weekly, keeping regular sleep times, having caffeine earlier in the day, eating regular meals and taking a short walk when you flag [2][3][4].
Does it take 21 days to form a habit?
No. In the UCL study it took 66 days on average, and a 2024 review advises expecting two to five months [1][5]. The 21 days came from plastic surgery patients getting used to their new faces.
What is the easiest healthy habit to start?
A small, simple action you can tie to your day, such as a glass of water with breakfast. Simple actions became automatic faster than bigger routines [1].
Is it better to build habits in the morning?
Possibly. Morning habits tended to be stronger in the studies reviewed, but the evidence is limited [5]. The best time is one that happens every day without fail.
How many habits should you start at once?
One is a good start. The UCL team's advice for GP patients is to pick one simple action and repeat it daily until it's automatic [1], then add the next.
How do you build a healthy routine?
Fix your getting-up and going-to-bed times first, then add one small habit at a time, each tied to something you already do [1][4].
References
Every study here is listed so you can read it yourself. This guide is for general information and doesn't replace advice from your GP or pharmacist. We review it when new research is published.
- Gardner B, Lally P, Wardle J (2012). Making health habitual: the psychology of 'habit-formation' and general practice. British Journal of General Practice 62(605): 664–666. PMID 23211256
- UK Chief Medical Officers. UK Chief Medical Officers' physical activity guidelines. Department of Health and Social Care, first published 7 September 2019, updated 10 July 2026. gov.uk/government/publications
- NHS. The Eatwell Guide. Accessed 17 October 2026. nhs.uk/live-well/eat-well
- NHS. Self-help tips to fight tiredness. Accessed 17 October 2026. nhs.uk/live-well/sleep-and-tiredness
- Singh B, Murphy A, Maher C, Smith AE (2024). Time to form a habit: a systematic review and meta-analysis of health behaviour habit formation and its determinants. Healthcare 12(23): 2488. PMID 39685110
