Sleep Hygiene - Part 3

In the last post about sleep hygiene tips (see here), we talked about how to use your bedroom (and your body temperature too!) to benefit your sleep.

In this post, we'll discuss tips related to diet. In summary:

As always, if you're already well-versed in how diet influences your sleep, it's up to you whether to continue reading this text or not. If you're curious, come along!

Be careful when eating at night 🥗, but also don't go to bed hungry.

How should you eat to improve sleep?

There is evidence that, in the short term, diets based primarily on carbohydrates are better for sleep than fat-based diets¹.

However, there is also research suggesting that a high-fat diet (such as the ketogenic diet) may have positive effects on sleep in the long term^{2 3}. Despite the potentially negative effect on sleep while following a diet like keto, the weight loss associated with it may be the factor that explains the sleep benefits over time.

So what should you do, cut fats and only eat carbs or cut carbs and only eat fats?

Hold on. We don't want you to take any drastic measures. Besides, when it comes to nutrition, balance is our motto!

Although science is always making new discoveries and still doesn't clearly tell us what we should eat, it has reached more solid conclusions about what we shouldn't eat.

As a starting point, the general idea is that eating foods with more saturated fat and sugar throughout the day, while having low fiber intake, is associated with lighter and less restorative sleep⁴.

So if you can gradually reduce your intake of these fats and sugars while increasing your fiber consumption throughout the day, that will already be very positive.

If you want an answer about what type of diet to follow, I can offer a few more suggestions.

Diet is not exactly the focus of cognitive behavioral therapy for insomnia (CBT-I), and this program is relatively short-term, so my main suggestion is that you don't start different diets at this time, particularly if you were interested in the information that the ketogenic diet can promote faster weight loss and improve sleep in the long term! A high-fat diet requires your body to adapt, which can take time and interfere with the results sought through CBT-I.

On the other hand, if you've already been following a high-fat diet for some time, it's up to you to reflect on whether it's been positive for you.

Why control fats in general and close to bedtime?

The main idea behind not eating fatty or spicy foods, especially at night, is to avoid gastric reflux that can cause awakenings during the night. Fats delay stomach emptying because they are harder to digest. In general, fats have twice the calories of carbohydrates and proteins, meaning they contribute more to weight gain. Additionally, excessive consumption, especially of saturated fats (from animal sources or fried foods), is associated with cardiovascular disease.

Well, although you shouldn't go to bed with a stuffed stomach, it also doesn't need to be empty. A stomach growling with hunger can also keep you awake.

How can you use this to your advantage?

For the purposes of this program, it's good enough if you gradually reduce foods that disrupt your sleep.

There are studies indicating that some foods may help promote sleep. Milk is an example of these types of foods because it contains tryptophan and melatonin. The list is long and includes foods like bananas, kiwi, almonds, among others.

We prefer not to go into details about consuming these foods because their effects on sleep promotion are very limited compared to other techniques covered in this program, and we also don't want you drinking milk thinking that's what will make you sleep.

Avoid excess liquids 🚰 at night.

Why does it help?

This one is simple!

Reducing water intake at night decreases your need to go to the bathroom during your sleep period. The suggested rule here is: have your last glass of water 2 hours before bed.

But since every bladder is different, do what feels best for you. If you never wake up at night to go to the bathroom, you can drink more water. If, however, even with 2 hours you've been waking up for this reason, increase this interval to 3 or 4 hours between your last glass of liquid and bedtime.

By the way, remember the idea of drinking tea at night? If you're drinking it right before bed, be careful to see if this is also disrupting your sleep!

Pay attention to when and how much caffeine you consume ☕️.

n Generally, people see caffeine as the villain of sleep.

This can be a mistake. Caffeine is actually a stimulant, but if used properly, it can help regulate your sleep. Like most things in life, it's a matter of "how much and when."

How can you use this to your advantage?

It depends on what you're trying to achieve:

• Morning coffee can substantially help combat the harmful effects of a poor night's sleep.
• Afternoon coffee can be used to combat the natural tendency toward that post-lunch drowsiness, especially if you've had a poor night's sleep.
• Early evening coffee can help you stay awake until later (especially important if you're practicing sleep restriction and having difficulty staying awake until bedtime).

The combination of the last two can later help increase "sleep pressure." And even better, if timed correctly, caffeine withdrawal can help people feel sleepy at times when they normally find it difficult to fall asleep.

The trick is figuring out how much is enough and when to stop. Obviously, this isn't an easy thing to do. It depends on your sensitivity (previous usage history), your body's metabolism, the amount of caffeine (or type of food containing it), and your willingness to discover through trial and error what works for you.

But if I drink coffee, how long will it keep me awake?

As mentioned, this varies greatly from person to person.

One study⁵ found that ingesting 200mg of caffeine influences our biological clock, delaying the rhythm of melatonin in our body by 40 minutes, almost half the delay caused by exposure to bright light.

With this, you can get an idea of how to use coffee to help you feel sleepy later, or reduce caffeine intake if you want to go to bed earlier.

However, if your goal is not to delay or advance your biological clock, the clinical effects of caffeine last 4 to 6 hours, so your last consumption should be 4 to 6 hours before bedtime.