My cousin was sitting across from me on the couch holding a bowl of purple grapes. The polite response would be to take a few.
I glanced at the bowl, then down at my watch. 9:30 PM. Too late. With a sigh, I raised my hand to wave off the fruit. My cousin shrugged and popped a grape into her mouth.
Should I explain myself?
No. Never complain, never explain.
The former British prime minister Benjamin Disraeli once said that. I have the quote on my fridge. Apparently it’s penetrated my subconscious.
And so I slouched back into my seat and kept my mouth shut.
But now that I’m removed from polite conversation, I think I’ll break with Disraeli. I mean, if I don’t explain anything on this blog, my claims won’t make any sense. Plus any credibility I have will spiral enthusiastically down the toilet.
So today I’m going to explain why I don’t put food in my body past 8 PM. If I do my job right, you might stop putting food in your body past 8 PM too. That would make me happy, because I write these articles for one reason: to help you optimize your health.
Time restricted eating
By not eating grapes past 8, I was practicing something called time restricted eating. Time restricted eating, as you might suspect, involves eating all your calories within a compressed time frame.
It’s pretty basic, but let me share how I do it anyway.
At night, I chew my last bite of dinner around 7 PM. That’s my last bite of the day. I don’t eat again until breakfast, usually around 9 AM. So I do a 14-hour daily fast. Put differently, I eat all my food within a 10-hour window.
The research on time restricted eating is overwhelmingly positive. Benefits include: weight loss, reduced inflammation, improvements in blood sugar, and even reduced cancer risk. Most of these benefits can be reduced to 2 mechanisms:
1) Circadian rhythm enhancement
2) Activation of internal repair processes
Get into the rhythm
The circadian rhythm – our 24-hour metabolic cycle – regulates nearly every function in our body. This cycle, explains biomedical researcher and blogger Dr. Rhonda Patrick, controls “everything from making neurotransmitters, to insulin, to glucose transport inside of cells, to oxidizing fatty acids, to repairing damage […] these clocks regulate thousands and thousands of genes which is somewhere in the neighborhood of around 10 to 15% of the expressed human genome”
So yeah, it’s crucial to get your circadian rhythm right. Most people know that light plays a major role here. Sunlight is the big one of course.
Sunlight wakes us up in the morning, and a lack of light in the evening helps trigger metabolic and hormonal changes that make us sleepy. But if we keep the lights on past dark, our body thinks it’s daytime. Blue light is not relaxing. You knew that already.
But many people don’t realize that food also affects our circadian rhythm. This is true because food regulates secondary clocks in the liver, fat cells, and elsewhere. Eating late throws off these clocks and can negatively impact metabolism.
A good strategy, then, is to eat breakfast with morning sunlight so the various circadian clocks can align. This helps with sleep, weight regulation, appetite, energy, etc. because: 1) hormones like leptin, ghrelin, and melatonin are rising and falling at the appropriate times and 2) your metabolism functions better.
The other reason I don’t eat past 8 PM? To repair.
During a human life, cells, DNA and proteins in the body become damaged. This damage has many causes: oxidative stress, environmental toxins, hyperglycemia, inflammation, and so on. The more damage we sustain, the more rapidly we deteriorate.
Under the right conditions, however, the body can repair some of this damage. Some examples:
Autophagy is when cells dispose of dysfunctional components and damaged proteins. In other words, autophagy is cellular cleanup. Mitophagy is similar. It’s when mitochondria – our cellular energy centers – clean up mitochondrial junk. DNA too can protect and repair itself, even after sustaining heavy damage. In this study, for example, researchers activated “protect and repair” genes in mice to shield them from massive doses of chemotherapy.
So how do you turn on autophagy, mitophagy, DNA repair, and other mechanisms to rid your body of damage? You fast. Fasting activates these processes. The chemo-protected mice were protected not because they were given an experimental drug, but because they were deprived of mouse pellets. Fasting was the drug.
Fasting for 12-14 hours a day is actually quite simple. You’re asleep most of the time. And to top it off, sleep quality is enhanced because your body can better repair itself in a fasted state.
Sleep quality is also enhanced because fasting helps with your circadian rhythm. But I won’t beat that horse any longer.
This explanation has gone on long enough.