An Expert Guide To Fine-Tuning Your Circadian Rhythm For Better Sleep

What if your best night’s sleep started with what you did in the daytime?

Nurturing your sleep cycle isn’t just about perfecting those bedtime rituals — the path to great sleep is often surprising, as your waking hours take equal precedence. We interview an expert in circadian rhythm to learn all the secrets

“48% of your brain is influenced by light, but only 10% by food.”

Introducing Daniel White

Sleep is a mysterious topic, and for many, a deeply confusing one — but it doesn’t have to be! Staying informed about the best sleep practices is the first step to conquering them.

Daniel is a Registered Nutritionist, Functional Medicine Certified Health Coach, and Sleep Specialist, with hands-on experience helping people from all walks of life make meaningful changes to improve their health and their sleep. After years of practising functional, holistic, and lifestyle medicine, Daniel was ultimately driven by his passion for teaching people how to transform their approach to sleep in order to live life to the fullest.

In this interview, you can expect to learn all about circadian rhythms and sleep, with practical tips, product recommendations, and truly insightful advice for living life with maximum potential — and on the best quality sleep possible!

“For 99% of human history, our sleep-wake cycles were governed by the natural light-dark rhythms of the sun. Sunlight in the morning helps regulate energy and mood, while darkness at night signals melatonin production for restful sleep. The modern world, with its artificial lights and screens, disrupts this natural rhythm.”

Transforming mind, body and soul with sound sleep

P: Hi Daniel, it's a pleasure to interview you about your work in the area of circadian rhythm and optimising sleep. I find it fascinating that you first practised as a nutritionist. How did you make the leap to becoming an expert in circadian rhythms and sleep? Was this journey a personal one for you?

D : "Yeah, great question, thank you. My journey into circadian rhythms and sleep science came from my own experience. It all started from the ages of around 13 to 17, when I was what you'd call a poster boy for disrupted sleep. I was really into video games, staying up till 3 or 4 AM, then dragging myself out of bed for school. That kind of lifestyle wrecked my sleep. I was obese, my mental health was terrible. Anxiety and depression ruled my life — and I was pretty disengaged from everything. At around 17, I knew something had to give. I then began a 14-year journey of studying psychology and nutrition. I sorted out a lot of my health issues through diet, and my professional life was thriving, but by the time I hit a bad case of burnout at 25, my sleep was still a mess. It was at this point I really deep dived into circadian science, and it completely transformed how I approached health and sleep. Now, I am fully committed to helping others optimise their sleep and circadian health."

Nutrition for optimising circadian rhythms

P: Wow, that's quite a journey, thanks for sharing that. I can imagine how challenging it must have been to balance all of those factors. It’s amazing that you’ve used that experience to help others. I wonder if you can tell me, what role does nutrition play in supporting circadian rhythms, from your perspective?

D: "Yeah, I will start with an amazing fact: 48% of your brain is influenced by light, but only 10% by food. I mention this because it really highlights just how important light is. The timing and type of light you expose yourself to directly affects everything from sleep to mood and energy levels.

However, even if it isn’t reflected in the quote I just provided, nutrition itself does play a massive role. From my standpoint and how I developed on my own personal journey with diet and lifestyle changes, finding a diet that helped me reach my sleep goals really was a huge step forward. When I got into the paleo and primal movements, I learned about anti-inflammatory diets and started cutting out processed foods, seed oils, and refined carbs. I also began eating nose-to-tail—organ meats, bone broth, all the nutrient-dense stuff that’s hard to come by. For me, it really helped my gut health and immune system. But that’s not all that needs to be considered in terms of sleep and nutrition. It’s not simply about getting nutrients alone. And it's not just what you are eating; it's when.

Eating at consistent times, aligned with daylight hours, is crucial for maintaining a healthy circadian rhythm. Late-night eating was not a typical habit of our ancestors, they found, cooked and ate their food in the daytime, or not long after sunset. As a result, nighttime eating can throw off your body’s internal clock through many other hormonal factors, such as hunger and satiety cues in the body. So, I always recommend people stop eating a few hours before bed, to avoid this pattern being upset."

Night owls, listen up…

P: That makes a lot of sense. The connection between timing and nutrition is something that often gets overlooked, I think. Moving on to another key area — light exposure — what does an ideal 24-hour light exposure plan look like, and especially for those living in cities with limited sunlight?

D : "Yeah… It’s a tricky one if I’m going to tell you the truth. The ideal setting would be to live on a campsite, getting light all the time, in nature, from the moment you wake up, but it simply isn’t possible for all of us. I live in an apartment block, nowhere near to the ground and there are awful artificial lights coming in the window from all directions when it gets dark. Realistically, it’s worth recognising and respecting that there is only so much a lot of people can do about this type of modern living, and to mitigate the effects with what is within their budgets to do so.

That said, light exposure is probably the most important factor in managing your circadian rhythm, and so it is 100% worth paying acute attention to. In the morning, you want to get outside and get sunlight within the first hour after waking up. If you're in a city with limited sunlight, use bright artificial lights, but sunlight is always best. At night, the opposite applies.

Also, if you’re using your phone or laptop in the evening, filtering blue light can make a huge difference to your sleep. On Apple devices, you can apply a colour filter or use apps like Flux on other platforms to reduce blue light exposure in the evening. I’m also a big fan of IrisTech . Their blue light filter is very good for reducing eye strain and improving sleep by minimising exposure.

Overall, it’s a simple concept and can be thought of like this — bright light in the day, minimal light at night."

P: Yeah we’ve all heard about the dangers of artificial light, I wonder if you offer more insights into this — how exactly does it harm our sleep, and what can we do about it?

D: "Exposure to artificial light at night, particularly blue and green light, blocks the production of melatonin (our sleep hormone) and raises cortisol levels (our stress response), making it harder to fall asleep.

Simple solutions like using amber or red lighting in the evening can help make big changes to the quality of our sleep and the health of our eyes. You can also filter out blue light from light blocking glasses, which you can use throughout the day too, and is something I would recommend to my clients."

P: It’s really great advice. How about on weekends? Should people be strict about maintaining their routines, or is there a little flexibility?

D : "Consistency is key, but life happens, right? If you're staying up later on weekends, try to keep the difference quite minimal. Avoid getting up past midday. You don't want to throw your whole rhythm off. The more regular your schedule, the easier it is for your body to stay on track. But you don’t need to be super regimented with it either, if you need to shift your sleep forward, by say, an hour or an hour and a half in order to enjoy your Friday night with friends — and then sleep the time back in the morning — so be it. You don’t need to keep getting up at 6 AM on the dot every single day for the sake of it. Scheduling sleep, I tell people, isn’t about reaching for perfection, it’s about progress."

P: I think a lot of people will appreciate that — it’s nice to know you can enjoy a bit of weekend freedom without ruining your whole week! Shifting gears a little — could you please explain how circadian rhythm affects memory and cognitive function?

D : "It's a very interesting point. Your brain consolidates memories while you sleep; if your sleep is disrupted, so is your memory. Poor circadian health can lead to cognitive decline over time. It’s one of the reasons optimising sleep is super important for long-term brain health. When you're not getting good sleep, especially deep sleep (now known as 3rd stage sleep), it interferes with how well your brain can store information and retrieve it later. I’ve seen so many clients notice real improvements in their memory and focus once their circadian rhythm is back on track. Sleep really is a foundational pillar of cognitive health. And it is a shame sleep isn’t valued more in society, for the sake of our wellbeing on a holistic level."

Sleep before midnight: An old wive’s tale?

P: One hundred percent, we should respect sleep more. Now, I can see how that gentle wake-up could make a big difference. How important is it, though, to get sleep before midnight? Does it really matter?

D : "Yes. Is it an old wive’s tale? In eras passed —midnight — as an expression, did actually refer to the middle of the night. People were usually in bed a lot earlier, without Netflix or iPhones keeping them up. And so, there is some truth to the saying that “sleep before midnight is worth double.” The earlier part of the night is when you get the most restorative, deep sleep, so going to bed earlier can help you wake up feeling more rested. Here’s why: your body’s production of melatonin, which regulates sleep, begins in the evening, peaking between midnight and 3 AM. If you’re still awake during this window, you’re missing out on that vital restorative sleep. So, in short, getting to bed earlier maximises that deep sleep, leaving you more energised the next day."

Solutions to seasonal affective disorder SAD

P: As we move into autumn and winter, then, people often struggle with Seasonal Affective Disorder (SAD). How can they maintain their circadian rhythm during the darker months?

D : "Light is always your best tool. In the darker months, remember you must still get natural light, where possible, before scrolling through your phone or opening the laptop screen — all emitting vast quantities of blue light. Getting outside as much as you can during daylight hours, even if it’s cloudy, helps too. And of course, having discipline in terms of keeping a regular sleep schedule is essential, in winter more so than ever. It is a difficult one, particularly if it’s pitch black and you have to make your way to work but, in these cases, I also recommend trying to work with what light you have. If possible, organise your day to get outside during those brighter hours, even if it’s just a 10-minute walk. These little habits, over time, make a big difference — especially for people who experience SAD. Basically, you can think of it like this: the closer you can stick to natural light patterns, the better."

Gimmick or pure genius: Can apps really help?

P: Thank you. It’s good to know that even a cloudy day can be of benefit! Another thing I would love to explore is the tech around sleep. There are so many sleep apps and devices out there now — what’s your take on using them? 

D : "It’s a growing industry, for sure. And yes, they can be useful for tracking general patterns, like how much sleep you’re getting and when you wake up. But they’re not perfect, especially when it comes to tracking REM or deep sleep stages. So, take the data with a pinch of salt — it’s good for overall trends, but don’t get too hung up on the details. For example, apps can give you insight into whether you're getting enough sleep or waking up frequently, but they might not tell you exactly how much deep sleep you’re getting. What’s more important is how you feel — are you waking up refreshed, or are you still groggy? That’s the real measure of good sleep. I would encourage people not to get too hung up on the data, as being too aware of it can actually really damage sleep. It is possible to get too orthodox about it all."

Cutting-edge light devices for better sleep

P: That’s reassuring — and yeah, sometimes it’s all too easy to get obsessed with the data! On another note, I have a Lumi. Personally, I like it and find it especially helpful as a SAD sufferer. Do you recommend them?

D : "Yeah, they definitely have their place, and the light they emit is a lot less severe than other lamps on the market. Alarm clocks like these can be put to good use, especially in the winter when natural sunlight is much harder to come by. They help you wake up more gradually, which is way better for your circadian rhythm (and nervous system) than being jolted awake by a regular alarm. And, the closer you can mimic natural light exposure, the better. So, these devices, like Lumi , create that gentle rise in light, similar to a sunrise, which helps your body transition out of sleep in a more peaceful way. This has a positive effect on your cortisol levels, making mornings feel a bit less harsh, compared to a traditional alarm clock."

P: On a similar note — what are your thoughts on using the more basic daylight or SAD lamps? Could they do more harm than good?

D : "While SAD or daylight lamps can be useful, yes, I do have concerns about some products due to the amount of blue light they emit — especially the cheaper ones. This intense blue light can raise cortisol levels and overstimulate the body, particularly when used first thing in the morning. Over time, excessive blue light exposure can also be harmful to the eyes. I’d opt for higher-end brands that tend to offer a more comprehensive light spectrum, including UV light, which better mimics natural sunlight and can be a safer, more balanced option. These lamps are less likely to cause the same level of overstimulation as lower-end models that rely heavily on blue light. That said, I’d still advise using them cautiously and supplementing with natural sunlight whenever possible — sunlight can never truly be substituted by a lamp."

P: Amazing advice. To wrap things up, may I ask what’s next for you in helping people with their circadian rhythm?

D: I’m really excited about what’s coming next — we’re launching the CRD Challenge, which is a 30-day programme to help people get their circadian rhythms back on track. It’s not just about better sleep, though that’s a huge part of it. We’ll cover everything from how to handle light exposure during the day, to tweaking your meal timing, to creating a routine that actually works for your body. Each week, we’ll dive into something new, like how to reduce artificial light at night or making sure you’re getting enough UV-A exposure during the day.

This challenge is deeply educational, with practical, science-based strategies that are easy to implement into your personal routines. So if you’re new to sleep hygiene or looking to step it up, I guarantee there’s something for everyone. I’d love for you to join us — see you all there!

Top SLEEP Picks right now:

A huge thank you to Daniel, for sharing such valuable insights on sleep and how we can all improve our circadian health. For those interested, Daniel will soon be launching the CRD Challenge — a practical, 30-day program aimed at helping participants through their personal circadian rhythm resets. The challenge is perfect for anyone looking to better their sleep patterns with easy, actionable steps for building consistent routines. Keep an eye out for its launch and Book a Call with Daniel here.

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