Most people believe that drinking 8 glasses of water (2000cc) a day is beneficial to health. However, in recent years, some medical research departments abroad have expressed different opinions. Many experts point out that it is not necessary to drink a full 8 glasses of water every day, and drinking too much water can also cause trouble for the body.
These experts believe that drinking water, like consuming calories, should be about replenishing what is needed. Currently, there is not enough scientific evidence to prove that drinking more water can detoxify the body more. On the contrary, drinking too much water can easily disrupt the body's electrolyte balance (causing a significant loss of sodium and potassium ions) and lead to a faster loss of water-soluble vitamins (such as Vitamin C and B vitamins). So, how much is too much or too little? How much water should a healthy person drink each day?
Scientific research indicates that, on average, the human body loses about 1800-2000cc of water daily through urine, sweat, or skin evaporation. Therefore, it has been believed that healthy adults need to replenish about 2000cc of water each day. However, these 2000cc of water do not have to come from drinking alone; the moisture in food should also be included, which is the correct way to maintain health.
In fact, the various foods we eat every day contain a lot of water. For example, most vegetables and fruits are over 90% water, and foods like eggs and fish contain about 75% water. Roughly estimating, from one meal, we can intake at least 300-400cc of water from food or soup. Therefore, after deducting the 1000-1200cc of water obtained from three meals, we only need to drink an additional 1000-1200cc of water each day, which is about 2 glasses in the morning and 2 glasses in the afternoon.
However, we should also know that the body's water demand depends on factors such as the environment (temperature, humidity), amount of exercise, health condition, and food intake, and there is no fixed standard value. Experts believe that the general principle for drinking water should be: no less than 500cc a day, but no more than 3000cc. However, some people do need to drink more water, such as those with gout or kidney stones. But the specific amount should also follow a doctor's advice. Is taking a daily multivitamin good for your health?
Previously, some nutrition experts reminded people that vitamins are not something to be taken in excess, and one should avoid single-nutrient supplements (such as Vitamin E, calcium tablets, etc.), but taking one daily multivitamin is relatively safe. However, many medical experts now warn that taking one daily multivitamin can also cause problems. This is because the doses of vitamins and minerals in some multivitamins far exceed safe levels, and more and more studies show that high doses of vitamins are not beneficial to health or disease prevention; on the contrary, they can increase the risk of certain diseases.
Recently, researchers from medical institutes in the U.S., UK, France, and other countries have pointed out that people with high concentrations of Vitamin A in their blood have a higher risk of developing osteoporosis. Other studies have found that excessive intake of Vitamin A increases the risk of fractures by 2 times. Moreover, the Vitamin A we consume accumulates in the body, unlike water-soluble vitamins, which are excreted in urine. The "Dietary Reference Intakes for Nutrients" issued by Taiwan's Department of Health and the "Tolerable Upper Intake Levels" set by the U.S. National Academy of Sciences stipulate that the daily intake of Vitamin A for adults (including from food and supplements) should not exceed 3000ug. However, in many multivitamins, a single tablet can contain up to 4500ug of Vitamin A, which is far above the safe upper limit.
In addition, when the human body consumes certain antioxidant vitamins (such as Vitamin C) in doses exceeding 500mg, they can become pro-oxidants, increasing oxidative stress and damaging cells. Excessive intake of minerals like iron can also increase the risk of heart disease and cancer. In some multivitamins, these substances also exceed safe levels. So, how should we safely choose and use multivitamins?
1. Check the ingredient list of the multivitamin. The amounts of various nutrients should meet (or be close to) the daily recommended intake set by health departments. Never take a multivitamin that is more than 150% of the daily recommended intake.
2. The product should clearly state the intended users, usage instructions, contraindications, and storage methods.
3. Purchase qualified products and check if information such as the manufacturer, importer, and contact details is clearly marked. Can people with high cholesterol not eat seafood?
It is often heard that people with high cholesterol cannot eat seafood because the cholesterol content in shrimp and shellfish is too high. However, nutrition experts point out that people with high cholesterol should pay more attention to their intake of foods high in saturated fat, because the effect of saturated fat on cholesterol is much greater than the cholesterol content in the food itself. The nutrition world generally uses the "Cholesterol-Saturated Fat Index" (CSI) to measure the impact of food on cholesterol, rather than just looking at the cholesterol content in the food. According to this index, the cholesterol content in shrimp and crab is actually similar to that in lean pork or skinless poultry. In comparison, fish and seafood have very low fat content. So, the key is how you eat?
1. Eat less foods high in saturated fat (such as fatty meat).
2. Try not to eat the heads and roe of seafood, where cholesterol is concentrated.
3. Eat less snacks and desserts that are high in saturated fat (such as ice cream, cake).
4. Maintain a balanced diet. There is no need to completely avoid certain foods; the key is to limit the intake of each type. Can eating fruit replace eating vegetables?
Some people who don't like to eat vegetables simply eat fruit instead. But can fruit really replace vegetables? Most experts disagree, because:
First, fruit has higher calories and sugar content than vegetables. Some people with chronic illnesses, such as diabetes or dyslipidemia, may even need to control their intake. Also, drinking fruit juice instead of eating fruit is not a good idea, as it can lead to the loss of important fiber.
Second, vegetables have higher mineral content. Green leafy vegetables, in particular, are rich in vitamins, minerals, and phytochemicals. In comparison, fruits contain mainly vitamins.
Third, a healthy diet emphasizes diversity; the more types of food you eat each day, the better. Even with vegetables, you shouldn't just eat green leafy ones; you should consume various kinds. The same goes for fruit; eating two different kinds daily and rotating them allows you to fully absorb the nutrients from different foods. Is the more dietary fiber you consume, the better?
The importance of dietary fiber for health is repeatedly emphasized. It sounds like the more fiber you consume, the better. If you think so, you are wrong.
Although dietary fiber helps prevent constipation, reduce the risk of cancer, lower blood lipids and cholesterol, and control blood sugar and weight, the ideal fiber intake should be 20-35 grams per day. Consuming more than this can have the opposite effect. This is because long-term, high intake of fiber can affect the absorption and utilization of important minerals in the body (such as calcium, iron, zinc, copper, etc.). Furthermore, fiber can make you feel full. When you eat too many high-fiber foods, they take up stomach space, reducing the intake of other foods. For people with small appetites or the elderly, this can easily lead to insufficient calorie intake and affect the consumption of protein, fat, and other important nutrients. Will eating a late-night snack definitely make you fat?
Many weight-loss tips tell us not to eat late-night snacks. However, foreign research surveys have found that the time of day you eat more food is not absolutely related to weight gain or loss. The U.S. Department of Agriculture divided a group of overweight women into two groups: one group consumed 70% of their daily calories before noon, while the other group ate near dinner time. The results showed no difference in their body fat percentage. Experts believe that weight gain is mainly because the calories consumed exceed the calories burned. Therefore, the most important thing for maintaining a healthy weight is to control the total daily calorie intake. So, can we feast on late-night snacks after a big dinner?
Experts believe this depends on an individual's lifestyle. Generally, it is more appropriate to consume more calories during periods of high activity. For office workers who go home after work and mostly lounge on the sofa or engage in sedentary activities, their calorie expenditure is much less than during the day. Therefore, nutrition experts believe that dinner should not be larger than breakfast or lunch. Late-night snacks or snacks eaten while watching TV often introduce extra calories, which will accumulate and lead to weight gain. This is especially bad if you go to sleep right after eating. During sleep, your metabolic rate drops by about 10%, so eating too close to bedtime theoretically makes it easier to store unused calories.
However, it is not entirely forbidden to eat a late-night snack. It is best to finish it 2 hours before sleep and avoid high-fat foods, as they slow down digestion and delay stomach emptying. The calories for a late-night snack should be controlled to about 200 kcal. Better choices include a glass of low-fat milk with 2-3 soda crackers, a light noodle soup, oatmeal, or red bean soup.