Circadian Personal

Let’s talk about Time-Restricted Eating

I have always been a good eater.

Back when I was in college—waking up at 4:50 am for crew practice, staying up until 1:00 am working on problem sets, and sleeping in until noon on my days off—I could eat pretty much any food in any amount at any time of the day. And I mean anything, anytime. Think: bootleg s’mores made out of saltine crackers and ice cream toppings. Cooked in the microwave. At 6:45 in the morning. 

Something changed in graduate school, when I stopped having wildly irregular sleep schedules and got my circadian act together. I just… didn’t feel hungry after a certain point in the evening. And if I tried to eat something very late in the day—say, a midnight snack— it actively made me feel… kinda bleh. 

My philosophy around food has always been to eat when you’re hungry. But once I was on a regular schedule, I stopped feeling the constant, slow-burning hunger I’d had back when I was up at all hours. I still felt hungry, but only at certain times of the day. The rest of the time I wouldn’t really feel hungry at all. You might say that my eating and hunger patterns became more strongly rhythmic.

Enter circadian rhythms. It makes sense to think that our bodies might be more prepared to handle food at some times (like when we’re awake), rather than others (like when we’re supposed to be asleep). And the same way light at night confuses and disrupts the central clock in our brain, so too could food around the clock confuse and disrupt the peripheral oscillators in our organs. Buying all this, how might you avoid this disruption? Eat what you want, but only over a portion of the day. 

This is time-restricted eating, or TRE: the idea of keeping all your eating to the same window of time every day. Usually this window is 8-10 hours long. So if you get up and start eating at 8:00 am, you might restrict your food intake to ten hours a day and stop meals after 6:00 pm. Or you might hold off on eating until 11:00 am, in which case you’d wrap up food for the day around 7 – 9:00 pm. You might only do this for five days of the week, or you might do it every day. Regardless, this isn’t about actively trying to cut calories. It’s not about how much you eat, it’s when. 

TRE came out of the work of Dr. Satchin Panda, a professor at The Salk Institute and author of The Circadian Code.

His group found that simply restricting eating windows led participants in their studies to feel more energetic, sleep better, and show improvements in cholesterol and blood sugar. He’s even got a research app you can download to participate in his group’s studies at (note: we’re not affiliated with this project, we’re just fans). 

Not everyone can manage TRE with their job (night shift workers, for one, often have to fuel whenever they can), and people with underlying health conditions should talk to doctors before giving it a try. But as someone who fell into a time-restricted eating schedule somewhat by accident, I have no plans of quitting anytime soon. I’ve lost a fair amount of weight since my undergraduate days, and it’s not because ever stopped eating s’moretines. I’ve just gotten to the point where my body has a much clearer signal than it used to for when it wants food and when it doesn’t. 

So take a look at Dr. Panda’s website, or book, and consider if TRE makes sense to try out. After all, the timing might be right for you. 

Circadian Lighting

Time to Win

Lately, I’ve been watching clips from the Olympics, getting misty-eyed when the athletes hug at the end, and then stalking the winners on social media: a normal Saturday night in 2021. I have a shirt that looks like that, I think as I scroll through photos of them lifting approximately three times my body weight. We’re not so different, you and I, I think as they hit a five-inch target from a football field away. 

Circadian Lighting Personal

The Right Light

I recently went on a trip to California.

Coming from the East Coast, this was a three-hour shift west. To adjust to California time, I needed to delay my circadian clock. One catch, though: my flight out was extremely early in the morning. That meant, like it or not, I was going to advance myself as I set out on the journey.

Let’s back up a little. We talk about directions your internal clock can shift as advances or delays. Think of advancing as hustling your clock along, making your circadian rhythms more like those of people in time zones east of you. Delaying, on the other hand, is like a temporary slowdown for your clock, making your rhythms more like people living to your west. Light at different times of the day advances or delays you, depending on your clock’s state when you’re exposed to it. 

Shift Work

Living with Shift Work

It’s no secret that working night shifts does a number on your body.

From increased risks of cardiovascular disease, diabetes, and cancer, to excessive alcohol consumption and worsened nutritional intake, shift work is associated with a whole host of nightmarish health effects. 

The simple solution would seem to be to get rid of jobs that put people on work schedules that are brutal to their well-being. But society needs 24-hour emergency and healthcare workers to function, which means night shift work is here to stay.

It’d be great if there was a pill you could take to erase shift work’s negative effects. Unfortunately, there’s not much in the way of pharmacological solutions that work for shift workers at present. There is hope, however: non-pill solutions, like changing shift timings and light therapy, can offer relief to shift workers. In this blog post, we’ll cover what we know about what works for shift workers.


Wearable Headaches (and how to fix them)

So you want to get somebody’s internal time from a wearable…

Let’s talk about wearable data. On the one hand, wearables are an incredible innovation, allowing self-quantification and anomaly detection with unprecedented ease, at unprecedented scales. 

On the other hand, they’re a data science nightmare. Or three nightmares, really. 

Nightmare #1: All the devices are different, and you have to use different ways to get raw data off them. 

Sure, apps like Apple Health that act as clearinghouses make this easier for you. But you can’t use Apple Health for everything. Sometimes, wearables require permission to be granted for you to access their full data. Sometimes, wearable companies go out of business after you’ve built an infrastructure to work with them. 

Can you process heart rate signals from two wearables using the same algorithm? What if they decide what counts as a “step” in different ways? What if the firmware changes? People have certainly thought about these questions, and that’s the whole point: you have to think about them. The effort of keeping track of everything adds up. 

About Arcascope

Welcome to Arcascope

Here’s the thing about the name:

I wanted to capture what I thought was most exciting about our company.

Sure, you can sleep better by taking care of your circadian rhythms, but circadian rhythms are about a lot more than just sleep

And yep, we’re a circadian rhythms company, but we’re one founded by people who are (primarily) mathematical biologists. 

Rather than trying to figure out what time is in a person’s brain with a gold standard test (for instance, by taking repeated saliva samples for hours in the dark), we use math models to infer what’s most likely to be going on in their brain, given all the inputs that have gone into it. 

Rather than trying to estimate their internal time from a single measurement or number, we use lots of data, collected on the timespan of weeks to months. 

In a sense, we’re using our algorithms to see inside a black box: letting us predict what’s going on in your head, without the need for invasive testing. That’s what I think is most cool about our tech.