Chrono-Nutrition: WHEN you eat impacts your sleep and energy

Hi there,

Welcome back to the third edition of my series on Chronotherapy—an approach that aligns your habits and environment with your body's natural rhythms.

This month, we’re tackling chrono-nutrition, or the science of when you eat and how it impacts your sleep, energy levels, and overall health. 

You already know that what you eat matters for your health, but did you know that when you eat can impact your metabolism, energy, and sleep just as much?

Many of us skip breakfast, eat late into the evening, or eat at irregular times due to work schedules or lifestyle habits. Some of you might have even radically shifted your eating rhythm this month for Ramadan.

Read on if you’ve ever wondered how these habits impact your health, longevity, sleep, and metabolism. Before offering some actionable tips, I will dive into chrono-nutrition and why it matters.

I have also compiled a pdf guide with the most important chrono-nutrition points to remember. By signing up to my regular newsletter, you'll get it straight into your inbox for free!

How Erratic Eating Disrupts Your Sleep and Health 

Our eating habits have become as unpredictable as our schedules in today's fast-paced world. A study by researchers Shubhroz Gill and Satchin Panda, published in Cell Metabolism, reveals that most adults eat erratically throughout the day rather than sticking to structured meal times. 

This eating pattern not only affects metabolism but it also influences sleep and overall health in profound ways.

A 15-Hour Eating Window—Too Long for Our Bodies?

In the first part of Gill and Panda’s study, 156 healthy men and women tracked their food intake over three weeks. Contrary to the traditional three-meal structure we might assume people stick to, it became clear that people tend to graze on food throughout their wakeful hours instead. 

The subjects also had a pretty long “eating window” –  the time that elapses between their first bite in the morning and their last bite at night. Most participants had an eating window of 15 hours or more.

Their eating was also skewed towards later in the day; they consumed less than 25% of their calories before noon while taking in more than 35% after 6 p.m. 

Additionally, the researchers saw that many participants shifted their eating rhythms between weekends and working days, for example, by delaying their breakfast by over two hours compared to the usual time. Brunch anyone? ;-)

This irregular eating pattern over the weekend creates what Gill and Panda call metabolic jetlag—a state similar to the desynchronization caused by frequent travel across time zones.

Does it matter?

The implications of this erratic eating are significant. Just as our bodies rely on a sleep-wake cycle, they also thrive on a predictable feeding-fasting rhythm. When this rhythm is disrupted—especially by late-night eating—it interferes with the body's ability to metabolize food, repair tissue, and regulate energy properly. 

The result? 

It can lead to an increased risk of weight gain, sluggish metabolism, and even poor sleep quality.

Can Time-Restricted Eating Be the Solution?

Next, to test the impact of time-restricted eating (TRE), the researchers piloted a new intervention: a small subgroup of the previous study—with increased BMI and big eating windows—was asked to reduce their eating window to 10 hours a day. So, for example, they didn’t eat before 8 a.m. and stopped eating at 6 p.m.

Gill and Panda specifically wanted to find out whether the timing of food (without changing diet quality or quantity!) could improve health. 

The results were promising—participants who followed this regimen for 16 weeks lost weight, felt more energetic, and reported improved sleep!

Even more striking, these benefits persisted a year later, indicating the potential for long-term health improvements simply by adjusting meal timing. Many participants were happy with their new routine and reported wanting to stick with it even after the study was over.

The Sleep and Metabolism Connection

Interestingly, the study found that fasting duration directly correlated with sleep duration. Those who ate for a shorter window had a longer overnight fasting period, which in turn promoted better sleep and metabolic health. 

Our internal clocks, or circadian rhythms, are deeply tied to when we eat. For instance, late-night snacking – especially snacks high in fat and carbs – can make it harder to fall asleep and can affect sleep quality.

Out of Balance: How Our Eating Habits Strayed from Evolution

Are you curious to hear more about how to synchronize your internal clocks and why our bodies are not built for our modern eating habits?

In my full e-mail newsletter, I dive further into the difference between our central and peripheral circadian clocks and give you a step-by-step guide on how to use scientific chrono-nutrition insights to boost your energy.

Especially if you often wake up sluggish in the morning or struggle with strong cravings during the day, this and April's newsletter will be interesting to you!

You can sign up for free by clicking here! You'll also gain access to previous editions of the newsletter.

Curious about new ways to boost your energy?

Learn how to improve your sleep or that of others. In this course I share the latest insights and practical techniques to help you or other people sleep better and thrive.

Click here to stay updated on my upcoming course!

Do you have experience with intermittent fasting, TRE, or fasting during Ramadan? I’m curious to hear about your experience and if you notice any differences in your sleep quality! 

Next month, we’ll dig even deeper into chrono-nutrition and discuss the perhaps most controversial meal of the day:

>> Breakfast.

Can what you eat right after waking up impact how you sleep during the next night? I’ll also introduce you to eTRE, maybe you can already guess what the ‘e’ stands for…

Until then, I wish you healthy eating and great sleep!

Dr. Els van der Helm