What if I now told you that many people struggle with weight loss not because they don’t eat right but because they don’t eat at the right time? When we eat is the key to health!
I hear you saying “What is this guy talking about!!”. And I used to think the same. But the last ten years since I am practising intermittent fasting I am able to listen a lot better to my body and what signals it is sending me throughout the day. And many of those signals very much related to timing! When I have energy, when I am hungry, when I am sleepy all are closely interlinked to how I feel.
There is a lot of science behind food and your circadian rhythm, so I invite you to join me in the magic world of the little clocks we all have inside us. When we eat is the key to health!
Making smart food choices is the key to eating and living healthy. But now, the more and more research shows that when we eat is just as important as what we eat.
Why, you ask? Because as it turns out, biological activities like metabolism are closely linked to our circadian rhythm. Your metabolism changes throughout the day because of your circadian rhythm or natural body clock.
Circadian rhythms are driven by a master clock, within the suprachiasmatic nuclei (SCN) of the hypothalamus, and peripheral clocks located throughout the body which govern most (if not all) of our body functions and when they should optimally take place . For the circadian system to function optimally, the individual clocks must be correctly synchronized to one another and to the external environment. Abnormal circadian rhythms are associated with poor health and metabolic disorders.
Your circadian rhythm is basically a 24-hour internal clock that is running in the background of your brain and cycles between sleepiness and alertness at regular intervals. It’s also known as your sleep/wake cycle.
Nothing in life and in our body works in isolation. We are very much connected with nature, and we are now discovering the impact it has to our hormones and our health. And the time of the day we eat has a strong influence to our digestion, our insulin and our sleep. We now know that certain genes turn on and off depending on the time of the day (and environment cues) in order to control almost every function in our body. All of this affects our hormones. Take for example cortisol and melatonin.
- In a perfect world, cortisol rises in the morning, peaks again in the afternoon right before lunchtime, and then drops at night.
- Melatonin does the opposite. It’s lowest in the morning and then gradually increases as the day goes on.
- That means, in theory, you wake up in the morning feeling energized and ready to go, then at night you start to feel sleepy and head off to bed.
Energy metabolism and appetite regulating hormones follow circadian rhythms which, when disrupted, could lead to adverse metabolic consequences.
Such circadian misalignment, a mismatch between circadian rhythms and behavior, is most typically experienced by people who do shift work, due to being aware in the night, sleeping during the day, and eating at constantly shifting times. Anyone who does shift work knows how exhausting this can be.
However, circadian misalignment is not restricted to shift workers; milder shifts in sleep and mealtimes, due social and eating behaviours, are highly prevalent in the general population. Social and eating jet lag result in later meal times, which will promote positive energy balance and weight gain. Earlier meal timing, specific to individual circadian patterns, could serve to reduce disease and aid in weight loss.
- Every organ in the body has an internal clock to determines which functions should happen at which time. For example when hormones are secreted. This is called circadian rhythm.
- Genes turn on and off depending on the circadian rhythm and environmental cues such as light.
- Shifting away from our optimal circadian rhythm can result to many issues, such as weight gain or metabolic diseases.
Food and circadian rhythm
Circadian rhythms, metabolism, and nutrition are intimately linked. We simply can’t avoid this fact.
In the morning
– The hypothalamus, is super sensitive to light. When your hypothalamus is exposed to light, it sends out signals to the rest of your body telling it that it’s time to wake up.
– In response to daylight and food, insulin sensitivity increases and melatonin decreases, making you feel alert and energized.
In the evening
- The hypothalamus signals to the body that it’s time to wind down.
- In turn, melatonin levels go up and insulin sensitivity decreases, preparing the body for rest and cell repair. It probably now starts to make sense that aligning the dinner time with our circadian rhythm can help maximize weight loss, improve endurance, reduce the risk of type 2 diabetes and lower blood pressure, among other things.
Insulin (as always) plays a crucial role here. When we eat, especially if we eat a meal that has a lot of carbohydrates, the body releases insulin in response to the rise in blood sugar. If insulin rises at odd times, like when eating a meal late at night, it can actually disrupt the circadian rhythm and increase the risk for long-term health problems. Insulin also promotes the storage of body fat, especially when eating too many carbohydrates or calories. Let’s be clear though here. The problem is not insulin, but the timing!
All of our cells and organs have clocks that determine when our genes should be turned on and turned off. The body can’t do all actions at once. So when the sun goes down, usually the actions of digestion are turned off and the actions of repair and restoration are turned on. If we eat late at night, we get slower digestion, inappropriate acid production, and more insulin resistance. This may be one of the key secrets that leads to fat gain.
But to make things even more complicated, remember that everything is interlinked! Sleep also affects two hormones in the body, which regulate hunger, ghrelin and leptin. Ghrelin stimulates appetite while leptin does the opposite. When the body is sleep-deprived it throws off the circadian rhythm, increasing ghrelin levels and decreasing leptin in the body—which will lead to increased hunger and sugar cravings. It is a vicious circle!
Sticking to eating during the day
On the other hand, sticking to an eating schedule that aligns with our natural hormone cycles and avoiding late-night insulin spikes can help reduce the risk of developing chronic diseases, type 2 diabetes, and heart disease. Do you want health benefits like
- Weight loss
- More efficient metabolism
- Increased energy
- Better digestion
- Reduced inflammation
- Improved immune function
- Timing your meals with your natural circadian rhythm has also been shown to help improve inflammatory diseases, like rheumatoid arthritis (or RA) and inflammatory bowel disease (or IBD), infections, metabolic disorders, infections, certain cancers, and central nervous system disorders, like multiple sclerosis and Parkinson’s disease.
We live in connection with nature and not against it. Follow the natural sleep-wake cycle has many health benefits.
When to eat
- Eat your carbs in the morning, when insulin sensitivity is the highest.
- Be consistent with your routine. The more regular your sleeping and eating habits are, the better your circadian rhythm works. The brain has memory and will expect what is coming based on your habits. Regulating eating patterns allows your body to anticipate and get to know that it can expect a glucose load at certain times of the day, so it’s prepped and can make the most appropriate responses.
- Eat no later than 7 p.m. If you are trying to lose weight and want to be healthy this is a key takeaway message. Additionally eating later in the evening is usually connected to snacking, and lower quality, junk food like pizza, pop-corn etc. And let’s emphasize that the amount of food is irrelevant. Even a single bite will trigger the digestion process!
- Remove artificial lights. Blue-light, extended screen time, and unpredictable sleep schedules can all negatively affect your natural circadian rhythm and throw your hormones out of whack. Eating with your natural sleep/wake cycles can help start to balance your hormones, but if you’re scrolling through Instagram on your phone until 2 a.m., it can negate your dietary efforts.
If you are still not convinced that this is the way we are built to live, then ask yourself “How did my ancestors live for the past 1 million years?” or “If I am out in the wild for a couple of days what would my schedule be?“.
Don’t try to fight how nature has so intelligently made us function. We are one with the environment. Respect that so you can thrive, reach your ideal weight and be full of energy. When we eat is as important to what we eat!