Different types of fasting schedules for your natural circadian rhythms

Intermittent fasting has gotten a lot of buzz over the years, so you’re probably aware of the benefits. But what many people don’t realize is that the timing of your fasting period is important, too. Aligning your fast with your body’s natural circadian rhythms can help you maximize the benefits and keep up the practice long term.

What are circadian rhythms?

Circadian rhythms are your body’s internal clock. They regulate the sleep-wake cycle, tell your body when to release hormones like cortisol and melatonin, help manage body temperature, and affect various cellular processes, from digestion to cell division.

External cues, especially light, help synchronize the body’s internal clock with the environment around you. This cycle repeats roughly every 24 hours.

Since they’re involved in so many of the body’s processes, disruptions to your circadian rhythms can throw off your sleep, mood, appetite, and cognitive function, which can have a significant impact on your overall health. 

Your chronotype affects your circadian rhythms

Circadian rhythms generally work alongside the 24-hour day, but the timing can vary from person to person. This helps explain why some people are more energized in the mornings, some prefer to be awake for hours before they eat anything, and others have trouble falling asleep before 11 p.m. 

The rhythms of your body drastically affect the rhythm of your day, and going against your natural rhythm will likely make your day more challenging. 

How circadian rhythms affect digestion, appetite, and metabolism

Our circadian rhythms run like clockwork, but eating at the wrong times can disrupt the timing and throw off your entire day.

Here are a few key principles to remember that will help keep your circadian rhythms steady.

The body needs 1–2 hours after waking before introducing food. Give your whole body a chance to adjust to being awake before eating breakfast. For some, waiting until lunchtime to eat might be best.

Digestion takes several hours. This is why it is generally recommended that you finish eating for the day at least three hours before going to bed. After-dinner snacks delay the restorative processes that happen while you sleep. Your body can’t get to these processes until the food you ate is digested.

Insulin sensitivity is greater earlier in the day. This means your body will be more able to process glucose in the morning and afternoon—so try to eat the majority of your carbs earlier in the day. Melatonin is secreted at night (in the absence of light), and also inhibits insulin secretion at this time. Eating when melatonin levels are high (such as late at night or early in the morning) can inhibit the body’s glucose response. 

If you can plan your days to consistently correlate with your natural circadian rhythms, this not only makes each day easier, but can also help you get more health benefits from intermittent fasting.

Best fasting period for morning larks: 6 p.m.–10 a.m.

For many, intermittent fasting means simply skipping breakfast. But if you’re up before the sun every day, waiting until lunch to break your fast might not be the best idea. 

If you need breakfast to fuel those early mornings, then by all means, eat breakfast, ideally around 10 a.m. Then, try to finish your last meal by 6 p.m. to give yourself a solid 16-hour fasting window.

Worried about getting hungry again before you go to bed? Be sure to drink Unicity Balance with dinner. It will help you feel fuller for longer so avoiding food for the rest of the day won’t be as hard. 

Best fasting period for night owls: 8 p.m.–noon

If you’re naturally more alert in the evenings, chances are you tend to eat later in the day, too—and think breakfast is overrated. So, the best intermittent fasting schedule for night owls tends to be one with a fasting window that starts later in the evening.

Finish your last meal of the day by 8 p.m., and then fast until noon the next day. If you still need something to help get you going in the mornings (a common need for those who aren’t built for mornings), that’s what Unimate is for. Just drink it after you get up in the morning to give you a boost to start your day and keep you satiated a while longer until you break your fast at lunchtime.

Best fasting period for third-birders (the in-betweeners): It depends

If you fall somewhere between morning larks and night owls, then either schedule could work well for you. You might want to try fasting windows with early and late starting times to see which schedule you like best. Pay special attention to your body’s hunger cues and energy levels. These are excellent clues on which times of day are best to fast, regardless of your chronotype.

Since your food intake influences your circadian rhythms (and therefore digestion and hunger), it’s important to keep a consistent fasting/eating schedule. Whether you start your fast early in the evening or after the sun sets, you’ll want to stick to that schedule (within an hour or two) every day of the week.

Intermittent fasting, personalized for you 

Intermittent fasting can be a powerful tool for improving your overall health. The more you can personalize it to your needs and lifestyle, the better off you’ll be. Aligning your fasting schedule with your circadian rhythms is a simple way to get more out of intermittent fasting—and to keep it a consistent part of your life so you can continue to maximize the benefits.