The circadian diet is all about light. No, not eating ‘light’ meals – but actual light, as in from the sun. It sounds confusing, but it’s actually pretty simple, so bear with us.
Put simply, it’s about eating with the sun. The key principle is that when we eat is equally as important as what we eat. The circadian rhythm is a roughly 24-hour cycle in the physiological processes of human beings – it regulates when we sleep and how we keep track of time.
Some scientists say that eating out of sync with your circadian rhythm can increase the risk of cardiovascular disease, diabetes and being overweight. But, by aligning your meals with your circadian rhythm, you can lose more weight, and improve your energy and overall health.
But how does it practically work? Does it mean you can just eat whatever you want as long as the sun is in the sky? Not exactly. The circadian diet demands that we eat during the day when the sun is shining- and fast during the night. Which actually means that for large parts of the year we would have to eat bigger meals in the morning. For many of us, it is already dark when we leave work during the winter – so the circadian diet would mean no food until we get back to our desk the next morning.
How to do the circadian diet Eat only when the sun is up and leave 12 hours between your last meal of the day and your first meal of the next day. Make breakfast and lunch your biggest meals of the day, and dinner the smallest. You should get 75% of your nutrition by mid-afternoon. Eat satisfying dinner foods for breakfast or lunch – pasta for breakfast shouldn’t be sniffed at.
What are the benefits of the circadian diet? Some studies have found that calories eaten in the morning might not actually count as much as those eaten at night. Findings suggest that people who eat most of their calories before 3 pm tend to lose more weight than people who eat most of their calories later in the day – which makes sense for this diet. Scientists are increasingly finding that our circadian rhythms do have a direct impact on our physical health.
Researchers are uncovering how the circadian clock directly affects the microbiome, and Washington University researchers just discovered an immune cell that sets the clock for the gut, suggesting why circadian rhythm disruptions are linked to gastrointestinal problems, obesity to colon cancer.
But experts are reluctant to sign-off on the benefits of this diet because there is no one-size-fits-all approach. ‘A circadian diet is also known more commonly as a type of intermittent fasting,’ explains Rhiannon Lambert RNutr, nutritionist and author. ‘Now, intermittent fasting may be an effective method of monitoring energy intake for some – by simply skipping a meal or eating only within a certain time-frame, you may consume fewer calories than usual over a period of time which may lead to successful weight loss.’
‘However, this really depends on a multitude of factors, your lifestyle, energy needs, can you keep eating in this way?’ Rhiannon says that a lot of her clients have found that this way of eating simply isn’t something they enjoy or want to stick to long-term. ‘That being said, if you don’t wake up hungry and you could easily miss breakfast without a second thought it may be a way of life that works for you, just remember it does not guarantee weight loss,’ she adds.
‘There is still no large body of evidence to support this approach and some studies suggesting benefits are conducted for those with type 2 diabetes, looking at insulin levels and appetite regulation which cannot be applied to the general public.’ She says the principles of eating more intuitively with the light sounds good in theory, but applying them to life is very different.
‘It is most definitely not something to encourage if you experience anxiety, have a history of disordered eating or an eating disorder, or have a medical condition and are on medication,’ she says.
‘The implications of a one-size-fits-all approach are very concerning for registered nutritionists and dietitians like myself. ‘They may sound like they offer the solution but the reality is we are all unique and our bodies deserve a bespoke approach.’
So, if you’re considering switching up your diet it’s important to remember that everybody has different needs. What works for your best mate, or your favourite influencer, might not be what your body needs.