Chrononutrition is the study of how nutrition relates to your body’s circadian rhythm, the internal clock that governs your body’s physical, mental, and emotional cycles. Your circadian rhythm is most affected by light and dark and affects sleep, body temperature, hormones and appetite.
Historically, humans ate during the daytime and slept during the nighttime, and their bodies would produce hormones based on the needs of the particular time (for example, to produce melatonin at night and cortisol during the day). Modern life does not always stick to the same schedule, and this can break the rhythm.
Irregular eating habits, especially late night eating and changing sleep schedules, can upset your circadian rhythm. Even exposure to artificial light at night can affect it! Fortunately, the body has a highly adaptive system. If you have traveled in more than one time zone, the delays you experience are re-adjusting the body’s rhythm to the new schedule.
Different people may have different chronotypes, often referred to as “internal clocks”. This can be affected by the same things that affect the circadian rhythm, as well as things like shift work, jet lag, and mood disorders. Identifying your chronotype is the first step to understanding whether your eating and sleeping habits are working for or against you.
There are three chronotypes: morning type, evening type and none. Morning types are those who get up early, wake up with the sun and sleep well at night. The evening type finds it difficult to wake up during the day and is more productive in the evening and at night. Most people fall somewhere in between.
Knowing your chronotype can also help you monitor your eating habits. A 2019 study looked at the link between chronotype, diet, and cardiometabolic health. The researchers found that identifying with an evening chronotype was “associated with lower fruit and vegetable intake and higher energy intake from energy drinks, alcoholic, sugary and caffeinated beverages, as well as fat.”
WHY DOES MEAL TIMING MAKE SO MUCH DIFFERENCE?
When your circadian rhythm is disrupted for any reason, it can affect the part of your brain that controls many important functions, including your ability to produce digestive enzymes such as amylase and pepsin, which are essential for nutrient absorption. If these functions are disrupted, it affects your ability to break down food properly and makes you feel hungry even when you’re not, which can lead to weight gain and other health problems.
Aligning your eating and sleeping habits with your body’s natural tendencies is a way to honor your bio-individuality, or the specific nutritional and lifestyle needs your body has. You may not even need to change your diet (although quality certainly does!) – simply adjust your meal times to support optimal metabolism and reduce the risk of weight gain and obesity-related conditions.
1. Plan a nutritious breakfast.
Many find themselves too busy to have a substantial breakfast and often grab a light bite on the go or wait until the next meal. This often leads to eating more later in the day. Research shows that a higher-calorie breakfast and a lower-calorie dinner can help support weight loss and reduce the risk of metabolic syndrome.
Try avocado and hard-boiled eggs with a slice of whole grain bread or oatmeal with walnuts, coconut flakes and strawberries to start the day in a hearty and nutritious way.
2. Establish a regular sleep schedule.
Sleeping during the day and working at night can affect the metabolism, leading to a greater chance of gaining weight. In fact, due to this phenomenon, people who work the night shift may experience changes in their weight even if their diet remains the same.
Whatever your schedule, try to sleep for about eight hours a day – it’s even better if it’s the same time every day. Create a calm, dark space where you can rest and have a restful sleep.
3. Eat smaller portions in the evening and enjoy larger portions of nutritious foods earlier in the day.
Larger meals in the evening are traditional in many cultures, but switching to a more hearty lunch and eating less in the evening can help support weight loss and improve insulin sensitivity, meaning your body will have an easier time maintaining proper blood sugar levels.
For dinner, experiment with smaller portions and lighter options, such as a nutritious soup, omelet, or veggie bowl, and eat more “dinner-sized” meals for lunch.
FREQUENCY AND FASTING
Recommended meal frequency varies from person to person and should be determined by you and your doctor as well as a nutritionist or dietitian. According to The Big Breakfast Study, your biggest meal should be breakfast, followed by lunch, then dinner, and those three meals should be the only meal of the day.
The study goes on to say that the gap between mealtimes is almost as important as mealtimes. Spreading out meals allows your digestive system to work most effectively at absorbing nutrients and balancing your metabolism. The study showed that the following eating/starvation cycle was most effective:
Have breakfast, then fast for 4-5 hours
Eat lunch, then fast for 5-6 hours
Have dinner, fast for at least 12 hours before breakfast the next day
Fasting for too long between meals and a constantly changing meal schedule can also lead to weight gain. Just like with sleep, it’s important to maintain a regular feeding schedule.
Benefits of chrononutrition
While there is no evidence that chrononutrition can cure diseases, it has proven to be a good tool for managing blood pressure and stabilizing blood sugar levels. Studies have shown the link between irregular glucose levels and circadian rhythm disturbances, increasing a person’s risk of type 2 diabetes. The American Heart Association says that “intentional eating by paying attention to the timing and frequency of eating opportunities can lead to healthier lifestyle and cardiometabolic risk factor management.”
working with your body
The most important thing is to listen to your body. Recognizing your hunger and satiety tails is the best way to know when to eat. Not hungry for breakfast first thing in the morning? Wait until you’re ready to eat and get the most out of it by loading up on fiber, fat, and protein (blackberry oatmeal and a scoop of peanut butter might work!). Do you feel hungry at 3 pm? Have a healthy snack to keep your energy levels high. Learning to time your meals according to your unique body will eventually make you more conscious of not only when you eat but also what you eat.