Try This – Two simple sleep hacks I shared with a friend last week

Last week, a friend reached out because he was still waking up groggy, even after focusing on the basics: cool, dark room, magnesium, no screens after 9 PM, blue-light blockers.

Sleep is tricky. Honestly, there are so many variables at play. But I suggested he explore two often-overlooked, very simple things that have made a difference in my own sleep.

If you or anyone you know struggles with sleep, keep reading. I want to share these tips with you, too.

Tip 1: Open Your Bedroom Window

Ever notice you sleep ridiculously well when you're camping?

Or how that vacation rental with the cracked window left you feeling more refreshed than you'd felt in months?

It's not just the change of scenery. It's the CO₂.

Outdoor air sits around 420 ppm CO₂. A sealed bedroom can climb past 2,000 ppm overnight as you and a partner exhale for eight hours straight.

Why does that matter?

Your brain monitors blood CO₂ levels and responds to elevations by increasing breathing rate. In a high-CO₂ environment, this constant low-level respiratory signal keeps the nervous system in a lighter sleep state, reducing slow-wave sleep and REM duration.

That means less deep sleep. More micro-arousals. And more foggy mornings.

One of the strongest studies on this comes from the Technical University of Denmark. 

The researchers recruited people living in single-occupancy dorm rooms and had them sleep under two different conditions for a week at a time: one with better nighttime ventilation (either by opening a window or using a quiet fan system) and one with poor ventilation. They then measured bedroom air quality using CO₂ levels as a marker of ventilation and tracked sleep using wrist-worn sleep monitors called actigraphs, along with morning questionnaires and next-day cognitive tests.

The difference in air quality was dramatic. Bedrooms with closed windows reached average CO₂ levels around 2,400–2,600 ppm, while better-ventilated rooms stayed closer to 660–835 ppm.

When air quality improved, participants:

• Fell asleep faster

• Felt less sleepy the next day

• Reported feeling more rested

• Experienced objectively better sleep quality

They even performed better on tests of concentration and logical thinking.

Same beds. Same students. Only the air changed.

Crack your window 2–3 inches before bed. If noise is an issue, run a fan that pulls air from another room.

And if you want to get fancy and monitor your CO₂ levels, check out the Airthings monitor (no affiliation). I have one in my bedroom as well as my son’s nursery, and it nudges me to open the windows when the CO₂ levels are too high. 

Tip 2: Stop Eating Three Hours Before Bed

This second one took my friend by surprise.

Most people don't realize how late they actually eat. A brand-new April 2026 study published in Nature Metabolism by Dr. Satchin Panda's lab at the Salk Institute analyzed more than 2.5 million food logs from over 21,000 adults across two weeks of real-time logging.

The findings were striking. The median eating window stretched 13 hours and 24 minutes. More than half of the respondents finished eating after 8:00 p.m. And only 5.2 percent of people ate their meals around the same time every day. 

Translation: Most of us are eating right up to bedtime and on no fixed schedule.

Why does that wreck your sleep?

When you eat late, your stomach is busy digesting while your body is trying to repair itself. 

In a study of men in Brazil, higher nocturnal fat intake from dinner plus late-night snacks was associated with lower sleep efficiency, longer sleep latency, and more wake time after falling asleep. 

Another review found that food intake within 30–60 minutes of bedtime negatively influences sleep quality, with a greater effect in women than men. And separate research in Arteriosclerosis, Thrombosis, and Vascular Biology found that eating your last meal three hours before bed is associated with lower blood pressure, lower heart rate, and better-controlled blood glucose.

Here's where Dr. Panda’s study gets really interesting:

People who pushed their eating window later didn't just eat at different times. They ate completely different foods. Late eaters who finished after 10:00 p.m. ranked beer, wine, ice cream, and cereal much higher in their food preferences. Early eaters who finished before 7:00 p.m. preferred walnuts, dark chocolate, and oatmeal.

The authors of the study point out that late eating windows raise the likelihood of consuming alcohol and energy-dense foods like ice cream in the late evening. These are exactly the foods that fragment your sleep.

My rule of thumb for sleep: no calories within three hours of bedtime. If you go to bed at 10:30 p.m., your last bite is at 7:30 p.m. Now, this doesn’t work great for people who wake up with really low blood sugar in the middle of the night. If that’s you, try a protein-rich snack, like nut butter with apples or celery, before bed. 

Pick One and Start This Week

If I had to pick just one for my friend, I'd start with the window. It requires zero willpower.

If you want to layer the second one in, close your kitchen three hours before bed.

Try it for seven days and notice how you feel in the morning.

Here's to your health,

Dhru

Much love,
Dhru Purohit 

The information in this newsletter is for educational purposes only and should not be construed as medical advice; please consult a qualified healthcare professional before making any health-related decisions.