Rule 3. Eating chronotype.
Food chronotype is the preferences of people associated with the time of day when they eat most of their calories. Scientists have found that the work of digestive system is closely connected with the system of our circadian rhythm. Not only the brain working as our central clock (a special part of brain called suprachiasmatic nucleus) but also liver, muscles, gastrointestinal tract, white adipose tissue and some other working as a peripheral clock, control the work of digestive system. The production of hormones, the insulin sensitivity, and the metabolic activity of liver change at different times of a day. In the process of evolution, the organism and its work has adapted to the day-night cycle. The activity of many genes changes in circadian rhythm.
Ideally, the eating window should coincide with the light window of the day and with the time of greatest activity of a person. The greater the divergence between the time of the eating window and the daylight hours, the greater the problems. Consume at least 80% of daily calories in the morning and afternoon.
The distribution of calories between breakfast, dinner and supper in the ratio of 50%, 30% and 20% contributes to better health. Scientific studies have shown that the same food eaten at different times of a day acts differently, and late plentiful suppers can increase the level of systemic inflammation, diabetes, tumors, and impair the quality of sleep.
How did the problem arise?
Delayed way of living. With the presence of artificial illumination, work in the morning and rest in the evening, our schedule of activity is gradually shifting to later hours, the so-called delayed way of living. In the morning we rush to work and skip breakfast, in the evening we eat plenty and fully. A lot of artificial lighting, especially LED light, block the production of melatonin, slow down the work of the internal clock, and disrupt appetite. The later the dinner, the less you are hungry at breakfast time, and a vicious circle is formed.
Nightly pleasures. Trying to get more pleasure, we start eating later in the evening. Food during the hours of darkness brings us more pleasure. This aspect is associated with the receptors of melatonin and dopamine in the brain. At night, the dopamine receptors are more sensitive and this leads to the fact that an eclair is tastier and the series are more interesting depending on how late they are. Therefore, people unconsciously get addicted to the late kaif. The less of joy and pleasure they have during the day the more they want to prolong the evening pleasure; as many say to live at least in the evening. Often a shift of the eating window leads to the night eating syndrome when people eat fully in the late evening and at night when they can hardly resist the arising impulses of hunger.
How does it affect heal?
Impaired carbohydrate metabolism. The important hormone insulin and the night hormone melatonin interact closely. Normally, melatonin and insulin levels are in a reciprocal relationship and if you have an evening attack with food and light, then your metabolism will definitely have problems. Indeed, high insulin can cut the level of melatonin and prevent its secretion. A decrease in melatonin and the decreased duration of sleep over time will reduce insulin sensitivity.
Insulin sensitivity. Good insulin sensitivity is associated with better health. In humans, the circadian rhythm regulates the insulin sensitivity and decreases it in the evening and at night. This process is connected not only with our central clock, the suprachiasmatic nucleus of the hypothalamus, but also with the peripheral clock of the liver, muscles, pancreas, and adipose tissue., In the morning and in the afternoon, the insulin sensitivity is biggest but by the evening it decreases both in adipose and muscle tissues, and in the liver. Those who consume a third or more of their daily calories after 18.00 have higher blood levels of glucose and glycated hemoglobin (a glycemic control marker), higher insulin, and a higher risk of diabetes and high blood pressure.
Combining a substantial breakfast and a light supper helps to control the level of glucose in blood better compared to the combination of a light breakfast and a hearty supper. The levels of insulin and glucose in the experimental groups differed by 20%.
Systemic inflammation and tumors. The higher the level of insulin and systemic inflammation, the higher the risk of cancer. Scientists have found that eating late in the evening increases the risk of breast cancer. Every other three hours that we do not eat until midnight, cut glycated hemoglobin by 20%. On the contrary, every 10% of calories eaten after 17.00 increases the level of inflammation (high-sensitivity C-reactive protein) by 3%.
Other problems and diseases. The habit of eating late increases the risks of obesity, sarcopenia (the loss of skeletal muscles), eating disorders, depression, and anxiety disorders. But the early eating window reduces the level of oxidative stress and evening appetite! Eating before sleep impairs the work of growth hormone (STH), which is associated with nocturnal autophagy (cellular self-cleaning). The more eating at night, the worse the sleep and recovery.
Move the eating window to the daytime. It’s good for your health to shift the eating window to an earlier hour by synchronizing the eating schedule and daily biorhythms. It is ideal to eat when you have a high blood level of cortisol, the hormone of activity and stress, and the lowest level of melatonin, the sleep hormone. By shifting the eating window we synchronize our circadian rhythms, and control appetite and hunger better. During the daylight hours the body has a better sensitivity to insulin so the food we eat is better absorbed and it reduces the risk of obesity and other health problems.
This method has different names, such as early Time-Restricted Feeding (eTRF), which is early feeding with a limited time. Traditionally, some practices use a similar shift in the eating window to keep up the clarity of mind. Buddhist monks are allowed to eat only until 12:00.
Remove the meals before sleep. Some people have the habit of drinking kefir or milk for good sleep, etc. Avoid this, no meals before bedtime.
Rearrangement of calories. Keeping the previous regime, begin to unload supper and increase the calorie content and the volume of breakfast and dinner. For many people, the dinner is the most substantial meal so save its volume to keep up satiety but cut the calorie intake. To do this, add more low-calorie foods: greens, raw vegetables, boiled vegetables. Add fats to stimulate the release of the cholecystokinin hormone, which maintains a feeling of satiety. For some people, proteins may also be nourishing but if you sleep not well avoided them for supper. Studies have shown that shifting calories from supper to breakfast while maintaining the meal times is a quite effective strategy.
Directly move the eating window. Shift breakfast and supper simultaneously for half an hour or an hour earlier. Do not go to extremes; a shift of even an hour is useful and will improve sleep. For us, the common purpose will be a smooth shift and evolution of your regime in the following sequence:
- do not eat before bedtime
- do not eat two hours before bedtime
- do not eat three hours before bedtime
- do not eat four hours before bedtime (you can reach five, but four hours is enough for the normal functioning of all hormones).
Example. You have breakfast at 11.00, supper at 21.00, and go to bed at 23.00. You can gradually shift your eating window in such way: 10.00 - 20.00, 9.00 - 19.00, 8.00 - 18.00. In this case, of course, you will have to shift your time of waking up and going to sleep
Thus, we can formulate our goal as follows: to finish the last meal before 16.00, but it’s also quite realistic and reasonable to finish it before 17.00 and even the classic do not eat after 18.00. For countries situated farther from the equator the schedule may vary depending on the season. So, the last possible evening time for supper is 19.00, and for mid-latitudes it is 20.00 in spring and summer because of longer daylight hours. At the same time, go to sleep no later than at 22.00, in the summer with a long daylight hours the time of 23.00 is possible.
Evening chronotype of nutrition. In some cases, the exceptions to the rule are possible. The hot weather in some countries makes people not willing to eat during the day, and the cultural traditions support this fact. In many cultures, the late dinner plays a social role when it gathers many relatives and friends at one table for communication and relaxation after work. People who work by evenings may also prefer the evening chronotype of nutrition.
How to follow the rule? Ideas and tips
Act smoothly. Changing your habits quickly is difficult and fraught with failure. Therefore, change your biorhythms smoothly and little by little. If you eat a little less for supper you will have more appetite for breakfast. The more you eat for breakfast the less hungry you will be before supper. Remember that evening overeating is laid in the morning. People who skip breakfast usually eat a lot late in the evening. Therefore, it is no sense to try not to eat in the evening if you have had poor breakfast and dinner, and to try to resist your hunger when you are tired and don’t have the resource of will power. You are sure to fail this way. So start your change with breakfast.
No appetite for breakfast? If you have no appetite for breakfast, then make a lighter supper or skip it. In such way you will have a great appetite for your breakfast and you can eat enough calories. Firstly, the appetite will be unstable, so you may force yourself to eat well. Even if you had a hearty dinner, don’t skip your breakfast.
Wake up a little earlier. If your schedule allows, wake up a little earlier. You should finish your breakfast before 8.00. This is not always and not for all possible rule. If you have the greatest work activity in the evening, such early breakfast may not suit you.
Have less cooked food at home. If you have problems with self-control in the evening, then keep less cooked food at home. Think can you have a dinner in a place with quality food on the way back home?
Have a breakfast plan. Think it over in the evening what and how you will cook for breakfast. If there is no plan, then you can probably make a tasteless and wrong breakfast is very high. Ideally, cooking should not take more than 20 minutes in the morning.
Have more fun during the day. Often, a wish to get pleasure after a joyless day pushes us to overeating in the evening. Therefore, be sure to plan at least one personal pleasure for every evening, and this will distract you from eating.
If you are eating your late supper. Ideally, eat and chew something raw with plenty of fiber, such as carrots. The process of thorough chewing can reduce stress and hunger. Raw plant foods (except fruits) with a little fat will have minimal negative impact, even consumed late in the evening.