Home > Living > Wellness > You’ve tried intermittent fasting, but what about the circadian rhythm diet?
You’ve tried intermittent fasting, but what about the circadian rhythm diet?

For decades, the premise of diets has revolved around what you eat, but in recent years, it’s all about when. 

Atkins dieters believed that carbs are the devil, Keto dieters are all about that high-fat lifestyle, while Paleo dieters won’t eat grains that didn’t exist before the agricultural revolution. Today, that focus has shifted from what we eat, but when we eat.

Everything that happens in our daily life revolves around the time of the day, and as much as we’d like to think that we have total control over our meals, a lot of what we eat and when we eat has been scheduled around work, appointments, and everything in between.

This pattern of eating means that people often find themselves eating at odd hours and often too close to bedtime, leaving their brains confused and their bodies struggling to keep up.

(Image credit: Malvestida Magazine/Unsplash)

Like sleeping, how we process food is also deeply reliant on the body’s circadian rhythm. Essentially an internal daily timetable, the cycle responds primarily to light and darkness, with sleeping at night and being awake during the day being the most common example. 

Chronically disrupted circadian rhythms not only affect sleep, but also prevent the body systems from working efficiently, leading to insulin resistance, fat storage, and increased risk of disease over time, which explains why the most widely touted preventative medicine today is at least eight hours of good sleep every night.

The concept

Chances are your eating pattern now lasts over 15 hours a day and well past dark, which clashes with the body’s release of melatonin and lowered insulin resistance as it prepares for sleep.

Like intermittent fasting, the circadian rhythm diet advocates time-restricted eating of your daily calories within an eight to 10 hour block when the sun is up, leaving a 14-hour fast between your last meal of the day and the first meal of the next day. 

(Image credit: Ben Kolde/Unsplash)

For this diet, experts have suggested swapping your dinner for breakfast. Instead of bagels or processed cereal as is the norm with breakfast foods, eggs and avocado with toast or a portion of salmon with pasta will help keep you more satisfied and less hangry thoughout the day, especially after the long overnight fast.

Lunch should be less heavy but with a good proportion of protein, fat, and healthy carbohydrates, while dinner should be the smallest meal of the day, especially as your body’s insulin sensitivity decreases before bed. Ideally, you should consume bout 75 percent of your nutrition before 3pm.

The benefits

No one likes being hungry and that’s why diets like these are hard to stick to. Quite begrudgingly, on behalf of the Lifestyle Asia team we sacrificed our happiness for the sake of an honest report, and followed the diet plan for two days. If you’re someone who’s used to small meals and lives for snacking in between, this diet will be a difficult one to get used to.

(Image credit: Travis Yewell/Unsplash)

The reported benefits, however, make it worth it. When the body is depleted of sugar, it taps into the body’s reserves, such as the carbohydrates that get stored in the liver. Fasting overnight allows the body to convert fat into ketone bodies, which fuel the brain and heart. Besides, your body isn’t struggling to digest your leftover pizza binge while also trying to repair itself. You’ll also be more inclined to skip dessert after dinner, which is truly a habit we could all get behind.

(Image credit: Andrew Tanglao/Unsplash)

Interestingly, the circadian rhythm applies for exercising too, with different benefits depending on when you work out. Exercising outside in the early morning can be a big mood booster, especially since that’s when your cortisol levels begin to rise before peaking midday. To fight the dreaded midday slum, a quick visit to the gym also brings oxygen back into the body after hours spent hunched over the desk while rushing deadlines. An evening sweat session, on the other hand, is associated with lower stress levels, better endurance and improved anaerobic performance, like for sprinting and resistance training.

Unlike many diets, the circadian rhythm diet isn’t about skipping meals or cutting calories. It’s about listening to what your body needs and not what your mind wants, and not eating during the time when you don’t need fuel can make a whole lot of difference to how your body takes on the day, whether the sun is up or not.

How do you follow the circadian rhythm diet?

The rule of thumb is to time your meals early in the day, preferably during the daylight hours and start your fasting before it gets dark or by 7pm. While following the diet, it is recommended to sleep and wake up at the same time every day for optimal functioning of the body’s sleep-wake clock.

Also, follow a healthy eating schedule to strengthen your internal clocks and maximise the benefits of the circadian rhythm diet.

Avoid consuming food at night as it can affect the production of melatonin hormone and disrupt our body’s natural circadian rhythm.

Difference between circadian rhythm diet and intermittent fasting

While intermittent fasting alternates between periods of fasting and eating, a circadian rhythm diet typically works on a set schedule. There’s usually a 12 to 16-hour fasting window in intermittent fasting, whereas the circadian diet is based on two time-restricted 12-hour windows — a fasting window between 7pm and 7am and a feeding window between 7am to 7pm.

You can choose your own fasting and feeding windows in the intermittent fasting method while the circadian diet entails a fasting window to align with the body’s internal clock.

This article was first published on Lifestyle Asia Singapore.

Lifestyle Asia
Here's where you can read the latest news and stories from Lifestyle Asia and our sister titles PrestigeOnline and Augustman, curated from all of our editions in Hong Kong, Singapore, Kuala Lumpur, Bangkok and India.