Optimize Circadian Rhythm with Time-Restricted Eating

Fitness isn't just about losing weight or gaining muscles. It is also about achieving optimal health, mental clarity, focus, high-quality sleep, gut health, absence of chronic diseases, and many more.

Traditional fitness plans often focus on regimens to prioritize calorie-burning exercises and protein-packed diets and emphasize 'what to eat.' While this approach is proven effective in weight loss and muscle building, how many fitness plans consider the impact of eating habits on mental health or the significance of meal timing for optimal digestion and sleep?

What if the key to better health isn't necessarily what you eat but when you eat it? Enter Time-Restricted Eating (TRE), a science-based eating pattern aligned with your body's natural circadian rhythm, allowing you to achieve weight loss and many other benefits.

This article will dive deep into the science of time-restricted eating and how you can use it to optimize your fitness journey and improve your overall health.

Time-restricted eating is a form of intermittent fasting that focuses on limiting the time frame to consume food rather than restricting your specific food choices or calorie intake.

Time-restricted eating sets a fasting window of about 12-16 hours per day where you cannot consume food besides water and an eating window of 8-12 hours where you can eat all your snacks and meals for the day. Note that some TRE plans allow unsweetened coffee or tea.

When done right, time-restricted eating can help you reduce weight and lose fat because you are more likely to achieve at least a 200-300 calorie deficit since your feeding time is limited and your fasting time is prolonged. In some studies, time-restricted eating results in at least a 20% reduction in total calorie intake.

Time-restricted eating is about limiting your eating window for the day to 8-10 hours.

Typically, you use glucose as your fuel to function in everyday tasks. However, when you fast for 12-16 hours, your body enters a state called "ketosis," wherein you burn stored fats and turn them into ketones to be used as alternative energy to power your daily activities.

This process effectively burns your stored fats, allowing you to achieve body recomposition and lose stubborn fat faster. In addition, this also allows your body to enter survival mode, resulting in the clean-up of damaged cells, cell repair, reduced inflammation, and regulation of sugar levels.

Time-restricted eating also goes beyond weight loss. It underscores the concept of circadian rhythm or our natural biological clock. The cells in our body have internal timings, allowing them to anticipate daily recurring and predictable changes, such as the availability of nutrients when we eat.

When you follow a consistent fasting and feeding window every day, you are synchronizing your eating habits with your internal body timings. This harmonizes with digestion, sleep, and

metabolism, resulting in a more holistic well-being.

Time-restricted eating can harmonize your eating habits with your natural biological clock.

Help manage weight

One of the most well-documented benefits of Time-Restricted Eating is its efficacy in weight management. By confining caloric intake to a specific window, you'll more likely consume fewer calories overall.

Furthermore, by aligning eating times with natural circadian rhythms when metabolism is at its peak, the body can process food more efficiently, potentially leading to better weight control and preventing weight fluctuations.

Limiting your feeding window can lead to a significant calorie deficit.

Your body uses up its stored energy when you follow Time-Restricted Eating and go for an extended period without eating. When you eat again, your body is ready to quickly use the food you consume to refill its energy stores.

This readiness makes your body use insulin more efficiently to move sugar from your blood into your cells, helping you regulate your blood sugar levels and prevent spikes. This is crucial for people managing or trying to prevent type 2 diabetes.

Time-restricted eating can help you regulate blood sugar levels.

Time-restricted eating promotes cellular repair processes and disposal of damaged cell components. This not only aids in maintaining healthy cells but is also associated with longer life and the absence of diseases. In addition, TRE helps to lower bad cholesterol levels and improves heart health.

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Studies have shown that irregular eating hours, particularly during weekends, can lead to chronic disruptions of circadian rhythm and hormonal levels, which increases the risks for chronic diseases such as cancer, diabetes, and heart disease.

Consistent eating routine within the same 8-10 hour time frame can increase lifespan.

Sticking to a consistent meal schedule can help you sleep better at night. Your body needs approximately 4 hours to thoroughly digest the food you eat.. Eating too close to bedtime can disrupt your natural sleep cycle because your body is still working hard to digest food rather than focusing your energy on restorative sleep and recovery.

Your body needs about 4 hours to completely digest and absorb nutrients from your last meal.

Your body goes into "energy-saving mode" when you fast for an extended period. Normally, you also consume significant energy in digesting the foods you eat. Since there's no food to digest, your body can redirect its saved energy to help your brain function more efficiently.

In addition, the ketones converted from fats act as a super-fuel for the brain, making you feel more focused and clear-headed. Some studies suggest ketones are a more efficient fuel source than glucose, especially during mentally taxing tasks.

Time-restricted fasting can improve focus.

Trillions of microbes live in harmony inside our gut, helping us absorb nutrients, manufacture immune cells, and create neurotransmitters found in the brain. Scientists refer to the gut as our second brain due to their impact on our mood and health.

Emerging research suggests that Time-Restricted Eating can positively impact gut health by encouraging a healthier gut microbiota composition. A balanced microbiome is associated with improved digestion, enhanced immune function, and management of anxiety and depression symptoms.

Time-restricted eating gives your microbiome time to rest and repopulate.

As part of our survival mechanism, a prolonged fasting period can stimulate the immune system and enhance our immune response. This process improves your body's ability to fight infections and diseases and helps manage inflammation.

Longer fasting window triggers clean up of damaged immune cells.

Here’s a plan for women to help you get stronger:

And for men:

Time-restricted eating is pretty straightforward. It is about building consistent habits and routines relating to your food and eating patterns. The idea is to subscribe to a 12-16 hour fasting period and consume your meals within the 8-10 hour eating window.

For example, consume your last meal at 8 pm and have your next meal by 12 pm tomorrow. This effectively gives you a 16-hour fasting window and 8 hour eating period.

Before implementing time-restricted eating or changing your diet, consult your medical provider especially if you have a chronic condition such as heart disease, diabetes, adrenal problems, and cancer.

Decide the timeframe within which you'll consume all your daily meals and snacks. This could be an 8-hour,10-hour, or 12-hour eating window. Ultimately, this will depend on your schedule and preference. Pick an eating window that suits your current routine.

Transitioning to prolonged fasting can be challenging at first. You must gradually adapt to this new routine and incorporate it into your daily life as smoothly as possible. To do this, try an 8-hour fasting window for the first few days, then transition to 10 hours, and so on.

Planning can eliminate the risks of temptation to break your fast. Ensure your meals contain balanced nutrition and a good mix of macros such as proteins, fats, and carbs. Remember to include nutritious fruits and vegetables.

Creating a routine around your food habits and eating patterns can make fasting mentally automatic instead of a burden. As much as possible, eat your meals at the same time each day to help you optimize your circadian rhythm.

This will also help your body anticipate your next meal time, making you feel hungry when it's actually time to eat. In essence, your body becomes more attuned to your eating schedule, and the hunger signals become more precise, eliminating the need for unnecessary snacking or overeating.

Fitness isn't just about achieving your desired physique. It is also about optimizing your health and wellness through a consistent eating routine.

Time-restricted eating (TRE) can effectively manage weight and improve different aspects of your health, such as metabolism, digestion, immunity, sleep, and cognitive functions.

Following consistent eating habits and routines can improve your health and reduce the risk of chronic diseases associated with irregular eating schedules.

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Bert Bauzon is a licensed physiotherapist specializing in spinal care and sports rehabilitation. He writes articles and books about exercise science and health care.

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