Most people believe that drinking eight glasses of water (about 2000ml) a day is beneficial for health.
However, in recent years, some reports from abroad have offered different opinions. Experts have pointed out that it is not necessary to drink a full eight glasses of water every day, and drinking too much water can also cause trouble for the body.
Nutrition experts state that, just like calorie intake, for water, "you should replace what you need." There is currently no scientific evidence to suggest that drinking more water can lead to more detoxification. Moreover, drinking too much water can lead to problems such as electrolyte imbalance (loss of large amounts of sodium and potassium ions) and the loss of water-soluble vitamins (such as B group and C).
So, what constitutes "too much" or "too little"? How much water should a healthy person drink daily? Scientific research indicates that the human body loses about 1800-2000ml of water daily through urine, sweat, or skin evaporation. This is why it is said that healthy adults need to supplement around 2000ml of water each day. However, this 2000ml of water does not have to come solely from drinking; the water in food should also be included. 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 estimated, from one meal, we can intake at least 300-400ml of water from food or soup. Therefore, after deducting the 1000-1200ml of water obtained from three meals, we only need to drink another 1000-1200ml of water a day, averaging two cups in the morning and two in the afternoon, to basically meet the requirement.
However, the body's water demand must be determined by individual factors such as environment (temperature, humidity), amount of exercise, health condition, and food intake, and there is no standard value. Some people do need to drink more water, including those with gout or kidney stones. The safest approach is to follow a doctor's advice. Are multivitamins good for your health?
There was once a popular medical science article that pointed out that vitamins are not something you can take more of for more benefit, so you shouldn't take single supplements like vitamin E or calcium tablets. However, you can take one multivitamin daily, which is safe and practical.
Now, however, some nutrition experts have issued warnings that even taking one multivitamin daily could be problematic.
This is because the amount of vitamins and minerals in some multivitamins is so high that it exceeds safe levels. Furthermore, an increasing number of studies indicate that high doses of vitamins are not beneficial for health or disease prevention and may even increase the risk of certain diseases.
For example, several recent large-scale studies abroad have shown that people with high concentrations of vitamin A in their blood have a higher risk of developing osteoporosis. Another study found that excessive intake of vitamin A doubles the risk of fractures. Moreover, the vitamin A we consume accumulates in the body, unlike water-soluble vitamins (such as B group and C), which are excreted in urine.
According to the "Upper Limits of Safe Intake" from the U.S. National Academy of Sciences, the daily intake of vitamin A for adults, from both food and supplements, should not exceed 3000 micrograms. However, some foreign multivitamins contain up to 4500 micrograms of vitamin A per tablet, which already exceeds the safe upper limit.
In addition, foreign studies have also found that some antioxidant vitamins, such as vitamin C, can become pro-oxidants when taken in high doses (over 500mg), increasing the body's oxidative stress and damaging cells.
Another mineral proven by research to increase the risk of heart disease and cancer when consumed in excess is "iron." Adults under 50 need 10mg of iron daily, while women need 15mg; for those over 50, the requirement for both genders is reduced to 10mg daily. The upper limit for intake is 40mg. Can people with high cholesterol not eat seafood?
It is often heard that people with high cholesterol levels say they cannot eat seafood because shrimp and shellfish contain too much cholesterol.
But in reality, nutrition experts say these people should pay more attention to meats and other foods high in saturated fat. This is because the effect of saturated fat in food on cholesterol is much greater than the cholesterol content of the food itself.
The nutrition world generally uses a "cholesterol-saturated fat index" to measure the impact of food on cholesterol, rather than just looking at the cholesterol content in the food.
If we look at this indicator, foods like shrimp and crab, which are generally considered high in cholesterol, are actually similar to lean red meat or skinless poultry. Furthermore, fish and seafood have very low fat content and contain unsaturated fats that are beneficial for heart health.
Therefore, for people with high cholesterol, you might consider eating this way:
1. Avoid red meats high in saturated fat (especially pork belly) and limit your intake of lean meat.
2. Do not eat the heads and roe of seafood, where cholesterol is concentrated.
3. Eat less snacks and desserts that are very high in saturated fat, such as ice cream and cake.
4. Finally, the age-old principle always holds true: pay attention to a balanced diet. If you have a concept of moderation, for example, eating it once a week and not excessively, you basically won't have a problem, and there's no need to completely avoid it. Can eating fruit replace eating vegetables?
Some people don't like to eat vegetables and simply eat fruit instead. But can fruit really replace vegetables?
Asking around, experts all disagree, because:
First, fruit has higher calories and sugar content than vegetables. Some people with chronic illnesses, such as diabetes or abnormal blood lipids, may even need to control their intake. Some people make the mistake of drinking fruit juice instead of eating fruit, which is even worse because it lacks important fiber.
Second, vegetables have higher mineral content, especially dark green leafy vegetables, which are rich in vitamins, minerals, and phytochemicals and are essential daily. In comparison, fruits contain more vitamins.
Third, one of the foundations of a healthy diet is "diversity," meaning the more types of food you eat each day, the better. Experts remind us that even with vegetables, it's not enough to just eat green leafy ones; you also need to consume red, yellow, orange, purple, and other different colored vegetables. The same goes for fruit: eat two different kinds daily and change them often to fully absorb the different nutrients from various foods.
However, the biggest advantage of fruit is that it can be eaten raw, without high-temperature cooking, making it easier to get some vitamins that are easily destroyed by heat, such as vitamin C and B group vitamins, than from vegetables. Is the more fiber you consume, the better?
Fiber is very important for health, and the idea of consuming more of it in your daily diet is repeatedly emphasized. It sounds as if the more fiber you eat, the better. If you think so, you are mistaken.
Although the benefits of fiber can be listed at length—including preventing constipation, reducing the risk of several cancers, lowering cholesterol and blood lipids, and helping control blood sugar and weight—the current recommended ideal intake of fiber is 20-35 grams per day. This is because long-term, high intake of fiber can hinder our absorption of important minerals such as calcium, iron, zinc, and copper. Not only that, oxalates and phytates in vegetables (one of the main sources of fiber) also affect the absorption and utilization of minerals.
Second, fiber is filling, so when you eat a lot of high-fiber foods, they take up stomach space, and you tend to eat less of other foods. This can lead to insufficient calorie intake, or poor intake of protein, fat, and other important nutrients for people with small appetites or the elderly. Will eating a late-night snack definitely make you fat?
Many weight-loss tips tell us that if we don't want to gain weight, we shouldn't eat too much at night, and we should say goodbye to late-night snacks. However, research surveys abroad have found that the time you eat more is not absolutely linked 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 did not affect their body fat percentage. Another large-scale official U.S. survey also pointed out that how much was eaten at night was unrelated to changes in weight over a 10-year period.
Experts believe that weight gain is mainly because more calories are consumed than are burned. Therefore, the most important thing for maintaining a healthy weight is to control the total daily calorie intake.
So, if we ask whether we can have a big late-night snack after a丰盛 dinner, it depends on an individual's lifestyle. Basically, it is more appropriate to consume more calories during times of higher activity. For office workers who go home after work, they mostly lounge on the sofa or do sedentary activities, burning few calories. Compared to daytime activity, nutrition experts believe dinner should not be larger than breakfast or lunch. Moreover, late-night snacks or snacks eaten while watching TV are often extra calories, which will accumulate and lead to weight gain. It's especially bad to go straight to sleep after eating. This is because our metabolic rate drops by about 10% during sleep, so theoretically, eating too close to bedtime makes it easier to store unused calories.
If you absolutely must have a late-night snack to fall asleep, it's best to finish it 2 hours before bedtime and avoid high-fat foods. Greasy food slows down digestion and delays stomach emptying, which can cause some people to sleep poorly at night and even affect their appetite the next morning, making them unable to eat the most important meal—breakfast. Keep the calories of your late-night snack around 200 kcal. Better choices: a glass of low-fat milk with 2-3 soda crackers, a light noodle soup or congee, oatmeal, or red bean soup.