Can drinking hot water help you lose weight? 15 questions about drinking water, all answered at once

This year's latest "Workplace Health Status Report - TalkingData" shows that among bad living habits, people in the workplace have the lowest awareness of "bad drinking habits".

Drinking water is definitely a trivial matter in daily life, but because it is a "trivial matter", many people do not pay attention to it, and the awareness is generally low. Most people still have various doubts about drinking water, and it is not easy to understand it.

This article sorts out 15 questions about drinking water, so you can understand them all at once.

1. Will drinking too much water cause "poisoning"?

Normally not

For those who don't like to drink water, they are always nagged to "drink more water" every day; and for those who love to drink water, they worry every day whether they will be "poisoned". How much water is appropriate to drink?

In fact, it is enough to drink enough water, and there is no need to drink too much. According to the recommendation of the "Dietary Guidelines for Chinese Residents", men and women should drink 1700 ml and 1500 ml of water per day respectively. Many people in life do not drink enough water, and for those who love to drink water, they often exceed this amount.

Generally speaking, as long as a healthy person has normal kidney function and does not have symptoms such as liver disease or congestive heart failure, water intoxication is rare. [1] So don’t worry, if you drink more, you will naturally pee more.

It should be noted that: avoid drinking a large amount of water in a short period of time to avoid hyponatremia and electrolyte imbalance. It is best to drink in stages, such as drinking a glass of water every half an hour.

2. Is it reasonable to wait until you are thirsty before drinking water?

unreasonable

Many people are used to waiting until they are thirsty to drink water, but this is not a good idea because when you are already feeling thirsty and have little urine output, it means that you have lost 2% of your body weight in water and your body is dehydrated. [1]

Therefore, don’t wait until you are thirsty to drink water. When drinking water, be sure to drink it slowly and in small sips, and don’t guzzle it.

3. Overnight water/thousand-times-boiled water cannot be drunk?

Can drink

There is a rumor that drinking overnight water or boiled water frequently can cause cancer. The reason is that it contains nitrite, which will further produce nitrosamines in the body after drinking, thereby increasing the risk of cancer. But in fact, whether it is boiled water or overnight water, it is safe to drink.

Someone has done a related experiment: after boiling tap water eight times, the nitrite content was only 3.38μg/L. [2] This is far from the nitrite content of drinking water specified in the "GB5749-2006 Drinking Water Hygiene Standard" of ≤ 1000μg/L, so there is no need to worry.

Therefore, as long as the tap water itself is hygienic, you can drink it with confidence.

4. Will drinking water after a meal affect digestion?

No

Some people believe that drinking water after a meal will dilute stomach acid and affect food digestion. In fact, this is not the case. Stomach acid is not so easily diluted. For example, a foreign document mentioned that drinking water before, during, or after a meal will not affect digestion. Instead, it will help improve digestion. [3]

In addition, some studies have mentioned: If we consider it purely from a biochemical point of view, it takes nearly 2 liters of water to cause changes in gastric juice. I guess no one would drink so much water all at once after a meal.

It’s okay to drink water after a meal, but be careful not to overdo it!

5. Is a glass of light salt water in the morning good for your health?

Drink with caution

According to the "Report on the Nutrition and Chronic Disease Status of Chinese Residents (2020)", although the salt intake of Chinese residents has dropped by 1.2 grams from 9.3 grams in 2015, it still exceeds the recommended amount of less than 6 grams, and more efforts are needed to control salt intake!

A cup of light salt water generally requires about 2g of salt, which is equivalent to the amount of salt for a meal. Especially for people who already suffer from high blood pressure, heart disease and abnormal kidney function, it is not recommended to drink it!

6. Is honey water nutritious?

No

Many people believe that honey is very nutritious. In fact, 75.6% of honey is sugar (including glucose and fructose), 22% is water, 2.3% is fat and protein, and less than 0.1% is vitamins, minerals, etc. [4]

Moreover, only 1 teaspoon of honey is usually used to make honey water, and the nutritional value is minimal. Not only does it have no health benefits, but drinking it frequently may even make you fat!

7. Can soda water cure stomach problems?

Can relieve, but not cure

For stomach discomfort caused by excessive gastric acid secretion, drinking soda water may help relieve it. However, even long-term drinking of soda water cannot cure stomach problems. If you have stomach problems, you still need to follow the doctor's advice for treatment.

8. Can drinking hot water help you lose weight?

Cannot

In order to increase metabolism, the body temperature must be raised, but the body temperature is constant, so drinking hot water does not increase metabolism. However, the results of a human experiment showed that drinking room temperature distilled water or saline did not increase metabolism, but drinking 3°C ice water increased metabolism by 4.5% and lasted for 60 minutes. [5]

However, increasing metabolism by just 4.5% will have little effect on weight loss, so don't count on it.

9. Can expired bottled water still be drunk?

cannot

Many people think that water should not be afraid of expiration and will not go bad. In fact, water also has a shelf life, and bottled water is generally 12 months. Although water itself is a very stable substance, the packaging container cannot keep its quality forever.

Bottled water is usually packaged in polyethylene terephthalate (PET), which is not toxic in itself, but can produce acetaldehyde after prolonged exposure to sunlight or storage at high temperatures for a long time, which can also contaminate water. [6]

Therefore, do not keep the bottled water you buy for too long and drink it up as soon as possible.

10. Purified water has no nutritional value. Should we drink mineral water?

No need to worry

Even mineral water does not contain many trace elements. The main purpose of drinking water is to replenish water, not to replenish trace elements. If you want to replenish trace elements, you should spend more time on consuming them through a balanced diet!

11. Can drinking water make people fat?

Won't

The premise of gaining weight is to consume too many calories, which leads to fat accumulation. Water has no calories, whether it is hot water, cold water or warm water, their calories are all 0.

Therefore, even if you drink a lot of water, you will not gain weight unless you drink "sugar water".

12. What temperature of water is more suitable for drinking?

Not exceeding 40℃

When we drink water, it passes through our esophagus. The esophageal mucosa is a very delicate part and is not sensitive to temperature. Even if we get scalded by drinking hot water, we don’t feel much. For the esophagus, the most suitable temperature is 10~40℃.

Drinking too hot water frequently will increase the risk of esophageal cancer. The International Agency for Research on Cancer (IARC) under the World Health Organization (WHO) has listed hot drinks over 65°C as Class 2A carcinogens, meaning they may cause cancer to humans.

13. Will drinking water before going to bed cause edema?

Won't

For healthy people who do not have liver, kidney, thyroid, heart, cancer or other diseases, drinking water before going to bed will not cause edema.

However, if you eat too much salt, it is possible! This is because excessive sodium intake will cause water retention in the body, so you will look a little "bloated".

Tip: Don’t drink too much water before going to bed, as you may be woken up by the urge to urinate.

14. Is there a best time to drink water?

No

Many people may have seen pictures such as "Best Water Drinking Schedule" on the Internet, saying that drinking water according to this schedule can "detoxify".

First of all, "detoxification" is a pseudo-concept. The body does not have so many "toxins" to be eliminated, and the human body has the ability to metabolize itself. In addition, you can set a time for yourself to drink water to help increase the amount of water you drink, but there is no strict requirement for drinking water at a certain time. There is no "best" time to drink water.

15. Is it easy to get kidney stones if you often drink water with scale?

No

Some people will have scale when they boil water at home. This is because the water quality is "hard", which means that the water contains high content of minerals such as calcium and magnesium. When boiling water, scale will form on the bottom and walls of the kettle.

Drinking such water regularly will not cause stones, nor will it harm your health. To prevent stones, you should prevent calcium oxalate, not calcium carbonate, magnesium carbonate, etc. in scale.

Tips for removing scale: Try vinegar or baking soda.

Summarize:

In a word, remember to drink more water!

References:

[1] Chinese Nutrition Society. Dietary Guidelines for Chinese Residents[M]. People's Medical Publishing House, 2016

[2] Wu Fei, Wang Hui, Shu Jingwei, Wang Anshuo, Chen Wenjun. Study on the correlation between residual chlorine and nitrite content in tap water and heating conditions[J]. Journal of Food Safety and Quality, 2017, 8(11): 4458-4462.

[3] https://hubpages.com/health/Drink-Water-While-Eating

[4] Yang Yuexin, Wang Guangya, Pan Xingchang. Editors. Chinese Food Composition Table. December 2009. 2nd edition.

[5]Brown CM, Dulloo AG, Montani JP. Water-induced thermogenesis reconsidered: the effects of osmolality and water temperature on energy expenditure after drinking. J Clin Endocrinol Metab. 2006 Sep;91(9):3598-602. doi: 10.1210/jc.2006-0407. Epub 2006 Jul 5. PMID: 16822824.

[6] Qin Jing, Chen Rongrong. Determination method of acetaldehyde content in PET bottled water and factors affecting the content [J]. Modern Food, 2016(01):99-101.