The best time to brush your teeth, eat breakfast and set your alarm (and it's not what you think)

Telegraph

22-05-2025

Dentists claim that using your toothbrush straight after breakfast could destroy the enamel on your teeth. So what other timings are we getting wrong in our daily routine?
Set your alarm
7.22am
We've all heard of entrepreneurs and fitness fanatics who wake at dawn to work out or hit their desks. Should you do the same? Maybe not. A study by the University of Westminster found that people who woke between 5.22am and 7.21am had higher levels of the stress hormone cortisol than those who slept later. They were also more likely to suffer from muscle aches, colds and headaches, and had worse moods.
This may be because they miss out on sleep, or because they are working against their chronotype – the genetically programmed tendency to be either a late-to-bed owl or an early-rising lark. Dr Neil Stanley, an independent sleep expert and the author of How to Sleep Well, says that while a 7am wake time is likely to be practical for most people, 'a recent study shows that the most important thing for longevity, even more than duration of sleep, is consistency of wake time.' This means, he says, that we should try to wake up at the same time, 'plus or minus one hour', every day, even at weekends.
Brush your teeth
Before breakfast
You might habitually reach for your toothbrush to scrub away toast crumbs and ensure a clean start to the day. But, says dentist Dr Shaadi Manouchehri, you could also be scouring away your precious dental enamel. She says that when we eat, the natural bacteria in our mouths produce acid to break down the sugar in food.
'So, if you brush your teeth, you are rubbing that acid on the tooth which is a mineral and it can wear it down,' she says. If you hate the idea of heading out without sparkling gnashers, either eat earlier so you can wait until an hour after eating before brushing or brush your teeth first.
Eat Breakfast
Before 8am
In 2023, a study of more than 100,000 people found that eating breakfast after 9am increases the risk of developing type 2 diabetes by 59 per cent compared to people who eat breakfast before 8am.
'We know that meal timing plays a key role in regulating circadian rhythms and glucose and lipid control,' said Anna Palomar Cros, a researcher at the Barcelona Institute for Global Health. 'Our results suggest that a first meal before 8am and a last meal before 7pm may help reduce the incidence of type 2 diabetes,' added Manolis Kogevinas, co-author of the study.
While another study showed that 9am breakfasters are 6 per cent more likely to develop cardiovascular disease than those who eat at 8am. They are also more likely to have healthy blood pressure and cholesterol levels. Dr Stanley says eating breakfast is 'a sign to your body it is daytime and is important for regulating your biological clock'.
Workouts
Morning for sleep and weight loss, afternoon for muscle gain
A recent US study has found that, for women, morning workouts between 6:30am and 8:30am reduced abdominal fat and reduced blood pressure. But evening workouts between 6pm and 8pm best enhanced endurance and built muscle.
For men, evening workouts were the most effective to burn fat and reduce blood pressure. Generally, studies have shown that scheduling morning exercise could help you stick to healthy exercise habits, shift your body clock to function earlier in the day, encourage more movement and enhance weight loss better than evening workouts.
Some research suggests that, compared to exercising at 7pm, a 7am run or other aerobic exercise may be key to better sleep and lower blood pressure. However, Dr Stanley says: 'You can exercise when you like without it affecting your sleep as long as you allow your body temperature and heart rate to return to normal before you go to bed, so have a cool-down stretch, maybe a shower and ease into your bedtime routine.'
One study even suggests that, over time, evening exercise can reduce levels of the 'hunger hormone' ghrelin.
Make an important decision or ask a favour
Between 11am and 12pm
Prof Russell Foster, a University of Oxford neuroscientist, is the author of Life Time: The New Science of the Body Clock, and How It Can Revolutionize Your Sleep and Health. 'Our cognitive ability and reaction time peaks between 11am and noon' he says, 'and our mood is also highest at this time, which means it's a good time to ask for a favour or a pay rise.'
Daniel Pink, the author of When: The Scientific Secrets of Perfect Timing, says that mood and alertness falls during the sluggish, grumpy post-lunch dip from 1pm to 4pm. And never fire off an important email in the small hours. 'Our cognition at 5am is worse than if we were drunk,' says Pink.
Take a nap
Between midday and 4pm
A recent UK study found that regular naps can help preserve reaction time and memory as we age – as well as leaving us feeling refreshed and more alert.
According to the Sleep Foundation, if your lifestyle allows, naps should be between 10 and 20 minutes long, and end before 2pm to avoid interfering with night-time sleep. A Japanese study showed that a 20-minute nap at 12.20 could wipe out the typical afternoon drop in energy. A cup of coffee before your nap can help you wake up naturally, as caffeine takes about 30 minutes to affect your system.
Drink coffee
After 9am and before 2pm
Caffeine blocks brain receptors that detect adenosine, a neurotransmitter in the body which builds up during the day and makes us feel sleepy. However, in the morning, adenosine levels are low, and the alerting hormone cortisol is high, so coffee might not give you the lift you expect. If you want to sleep well, avoid coffee after 2pm as it can take eight hours or more to be fully metabolised.
However, Dr Stanley says: 'Some people are more sensitive to caffeine than others, so if you sleep perfectly well after a late-night espresso, keep drinking it. If you know you won't sleep well, skip it.'
Eat Dinner
7pm to 8pm
Eating late – around 10pm – can increase the risk of weight gain and the risk of diabetes. Scientists in Spain found that people who ate dinner within two hours of bedtime were five times more likely to be obese than early diners. Prof Foster says: 'We are programmed to deal with calories and sugar much better during the first half of the day than the second. If you eat late, you are more likely to lay down calories as stored fat and to store glucose in the liver. It's best to eat a large breakfast and lunch and a small evening meal.'
Dr Stanley says: 'We need to lose one degree of body temperature to fall asleep. Burning calories creates heat so a late large meal will warm you up when you should be cooling down. Ideally you should eat no later than three hours before bedtime.' However, you also don't want to go to bed hungry as this can prevent you from dropping off. 'A small bedtime snack is fine,' says Dr Stanley.
Go to sleep
10pm to 11pm
According to research published in the European Heart Journal, a bedtime between 10pm and 11pm may cut your risk of heart and circulatory disease compared to people who hit the hay later. People who fall asleep after midnight have a 25 per cent higher risk of heart attack and stroke compared to early sleepers. Ideally, we should sleep between six and eight hours a night on average, though, says Prof Foster, 'some people may need as much as 10'.
Depending on how much sleep you think you need, you can count back from your wake time to find your ideal bedtime. 'Sleep is the foundation of physical, mental and emotional health,' says Dr Stanley. 'Never underestimate the importance of a good night's sleep.'
Tips for sticking to a daily routine
Choose the right habits
Make it easy to follow
Plan it all out (and have a backup plan)
Make sure you don't forget things
Try 'temptation bundling'
It's one thing to understand how to organise your day and quite another to follow through with your plan. First of all, 'make sure it actually works for you and is the right routine,' says Dr Phillippa Lally, an expert in habit formation and a senior lecturer in psychology at the University of Surrey. 'You might well want to exercise each day, but there's no point in telling yourself that you'll go out and run a 10k every morning if you really hate running.'
Dr Lally also recommends that you 'remove the friction' involved in getting the different parts of your daily routine done. This means 'making it as easy for yourself as possible': for example, if you want to eat dinner before 8pm, make sure that you have the ingredients you need to cook in your fridge already to avoid a stop at the shops. This is down to having a plan, too. 'Having a plan for your habits makes it an easy decision to follow them,' Dr Lally says.
Of course, it's also easy to forget to carry out some habits, like flossing or going for a walk in your lunch break, which you might not be so used to doing daily. The sage advice to set a reminder on your phone does help here, but it can also be helpful 'to tell a friend or family remember to remind you or ask them to do it with you,' says Dr Lally. Try this along with 'temptation bundling', which involves having a rule that you only get to do or have something you enjoy when it comes with the habit you're trying to build, such as listening to a gripping new audiobook only when you hit the gym.