1. Late-night Eating
Late-night eating is the primary cause of uncontrollable weight gain. The body's metabolism tends to slow down at the end of the day, so if you eat too late, the food will be difficult to digest. Instead of converting into energy, these foods metabolize into fat, especially accumulating in the lower abdomen. If this condition persists, the risk of obesity is very high.
Late-night eating forces the stomach to work harder to digest food. The stomach continuously works like this while you sleep, making it impossible for the body to rest completely and leading to difficulty falling asleep, fragmented sleep. In particular, if you eat late at night for several consecutive nights, it will disrupt the biological clock, causing you to wake up in the middle of the night.
After late-night eating, lying down immediately will likely lead to acid reflux. Stomach acid refluxing up the esophagus not only causes heartburn but also causes prolonged chest pain, leading to various other harmful issues. Therefore, the most appropriate dinner time is before 7 PM.

2. Wearing Too Tight Clothes
At night is the time for rest and a comfortable sleep. However, it won't be comfortable if you wear clothes that are too tight to sleep in. Wearing clothes that are too tight generates heat and affects blood circulation, causing body aches. Therefore, you should wear loose and comfortable clothes to facilitate better blood circulation.
The most important criterion for sleepwear is spaciousness. Wearing tight, constricting clothes poses a risk to overall health. Firstly, it negatively impacts blood circulation, obstructing the breathing process throughout the night. Additionally, the skin needs to breathe, so wearing tight clothes can cause skin irritation and even infection due to trapped sweat.

3. Using Stimulants
Stimulants referred to here are alcohol, beer, coffee, tea, or cigarettes. Caffeine and nicotine affect the central nervous system, stimulate the heart rate, and increase blood pressure. Moreover, these addictive substances also stimulate excitement, causing insomnia and significantly affecting body regulation. On the other hand, caffeine has a diuretic effect, so if consumed late at night (after 9 pm), it will lead to nocturia.
Most people who drink alcohol before bed quickly fall into a shallow sleep, but the quality of sleep is poor. Sleep is hazy, not deep because the stomach and liver are still active. Additionally, excessive alcohol consumption dehydrates the body, leading to fatigue. The initial effect of alcohol on sleep is prolonged sleep, but waking up still feels tired due to poor sleep quality.

4. Exposure to Electronic Devices
After a hard day's work, many people have the habit of relaxing by turning off the lights, turning on their phones, and browsing the internet before sleeping. However, through numerous studies, healthcare experts have found that blue light from mobile phone screens can be the cause of human retinal cell death and affect vision. When we use mobile phones in a dark or low-light room (for a long time), the electrical rays will shine directly into our eyes. It will cause dry macular for a long time, and ultimately can lead to eye cancer and blindness.
Evening is the time for relaxation, so exposure to phones and computers is unavoidable. However, you should limit exposure to these devices after 9 pm because they have a very negative impact on your health. The electromagnetic waves emitted from electronic devices during this time will disrupt sleep, making you always feel anxious, sleepless, or having disturbed dreams.

5. Drinking Milk
Drinking milk in the evening is very beneficial for health, but after 9 pm, it can cause undesirable effects. Drinking milk before sleep will create difficulties for digestion and also have a negative impact on tooth enamel. Milk contains a lot of lactose, which can cause blood vessel blockage, making blood circulation difficult, and this will wake you up at night.
Drinking milk about 3 hours before bedtime may be beneficial. But it's not good to sleep immediately after drinking milk. Also, it's not advisable to drink a large amount of milk before bed as it may affect the digestive system.

6. Showering
During the evening (night), the temperature and air decrease so showering at night will not be beneficial, even harmful to health. This can cause various mild symptoms such as headaches, neck and shoulder pain, leg and arm movement difficulties. In severe cases, dangerous conditions such as strokes, seizures, and death may occur.
Youth showering at night will cause blood vessels to contract, especially when using cold water, making blood circulation difficult, leading to headaches, neck and shoulder pain, and gradually becoming chronic headaches. Elderly people have physiological characteristics such as contracted blood vessels, arteriosclerosis, thicker blood, and higher blood viscosity than young people, so they often suffer from high blood pressure. If they shower late at night, they are very likely to have a stroke, much higher than young people.
After around 9 p.m., you should never take a shower, especially in winter. This is because sleep often comes when the body temperature drops slightly below normal. If you shower, hot water will increase body temperature, inhibit the release of sleep-inducing hormones. Of course, your sleep will be most affected.

7. Drinking Too Much Water
You shouldn't drink too much water at night, especially after 9 p.m. because it will cause you to wake up several times at night to urinate. This will disrupt your sleep and leave you feeling extremely tired the next day. Furthermore, your work will be very difficult to complete well if you are not alert and comfortable.
The human body can retain water if you drink too much water before bed. This can affect the urinary and circulatory systems. Increased water volume in the body at night can lead to serious issues such as urinary tract infections. If you drink 2-3 glasses of water in the evening, the excess water in your body will be excreted through the kidneys. This reduces the hormone ADH, making you feel bladder fullness and needing to wake up frequently to urinate, disrupting sleep.

8. Taking Calcium/Vitamin Supplements
Many people often have the habit of taking supplements before bedtime, but this can burden the stomach at night. Basically, you should not use therapeutic drugs or vitamin supplements after 9 p.m. During sleep, metabolic functions are resting, so taking supplements is often not beneficial for nutrient absorption, leading to reduced effectiveness.
Calcium is a mineral essential for the body, necessary for bone development, strengthening bones, teeth, preventing osteoporosis, rickets, bone softening, and brittleness... If the diet is deficient in calcium, especially during periods of increased calcium needs (children in the growth period, pregnant women, breastfeeding mothers, the elderly...) calcium supplementation is necessary. However, you should not take calcium in the afternoon or evening because calcium is prone to precipitate and accumulate, forming calcium oxalate which increases the risk of other diseases such as kidney stones, urinary stones, constipation, and notably insomnia, restlessness in children.

9. Overworking
The period after 9 p.m. is when your body starts to rest and prepare for the most comfortable sleep. However, if you engage in heavy work after this time, it will only make your body more tired, the nervous system is more likely to be damaged, and especially you are prone to illness. Therefore, you need to take some time to rest after a tiring day of work, to recharge for tomorrow.
Overworking will lead to insomnia, sleeplessness. Overworking makes your brain unable to rest properly, even without the opportunity to rest. So, don't try to work hard before going to bed and establish suitable nighttime habits for yourself.

10. Intense Workout
Exercising is something you should maintain daily but you shouldn't exercise close to bedtime. During the period after 9 p.m., deliberately engaging in intense workouts will stimulate the brain and increase excitement, raising cortisol levels.
For some reason if you have to perform physical exercise or any other workout at night, try to arrange to complete it before 9 p.m. Because after 9 p.m., physical exercise will not be good for your health. So, before going to bed, you should meditate to calm your mind and relax your body, which will be better for mental relaxation.

11. Watching Stimulating Programs
From around 11 p.m. to 6 a.m. the next morning is the best time to sleep. Therefore, going to bed before 11 p.m. is crucial to help your body enter the best state of rest.
Furthermore, after 9 p.m., you should avoid getting mentally stimulated. Avoid watching stimulating programs like horror movies, action films, or karaoke singing... as they can overstimulate the brain, leading to difficulty falling asleep or experiencing nightmares at night. This can also leave you feeling dizzy and demotivated when waking up in the morning.

