El ayuno excesivo tras las festividades puede afectar tu salud

Production: Popular Science China

Author: Maibo

Producer: Guangdong Provincial Association of Science and Technology.

Recently, many articles have appeared online about how to lose weight through intermittent fasting, with many people copying these methods. However, some individuals feel that this weight loss method is too slow, and have started sharing a method online that consists of eating only three types of fruits daily. Professor Chen Chaogang, Director of the Clinical Nutrition Department at Sun Yat-sen Memorial Hospital of Zhongshan University, pointed out that excessive dieting is not 'intermittent fasting'. Weight loss should be pursued in a healthy and comfortable living state; otherwise, it is easy to rebound!

Intermittent fasting is a scientific method of weight loss.

Chen Chaogang stated that intermittent fasting is a way to lose weight, involving strict control of dietary calories and the breakdown of body fat to provide energy. Scientific research has shown that intermittent fasting can not only be effective for weight loss but also reduce the risk of type 2 diabetes, improve brain health, strengthen the immune system, promote gastrointestinal health, and improve circadian rhythm, among other benefits. However, it does not mean 'not eating anything or only eating a small amount of food every day'. It is about eating scientifically according to personal circumstances and supplementing with moderate exercise, especially strictly regulating calorie intake at appropriate times.

'There are those online who present a diet method where you eat three apples a day, one with each meal. Can this be considered intermittent fasting?' In response to a journalist's question, Chen Chaogang firmly denied: 'Intermittent fasting is a scientific weight loss method; what you mentioned is extreme fasting, not intermittent fasting.' He explained that there are primarily four types of intermittent fasting. The first is the 5:2 method, which is the most recommended. It consists of maintaining a normal diet for five days a week (scientists recommend the Mediterranean diet) and choosing two days to reduce caloric intake to 25%, meaning that on intermittent fasting days, women should consume 500 calories, and men 600 calories.

The second mode is the 12:12 intermittent fasting method, which involves fasting for 12 hours a day. The simplest way to practice it is to include sleep time within the fasting window. For example, if you have dinner before 7 PM and breakfast after 7 AM, you will achieve 12 hours of fasting. This type of fasting primarily does not work by reducing caloric intake, but relies on regulating the circadian rhythm. If one eats after 9 PM, even following the 12:12 rule, one will not obtain the benefits this fasting method offers. Moreover, this method may have a slower weight loss effect, so it is often combined with other approaches.

The third option is the 16:8 intermittent fasting method, which limits the fasting time to 16 hours. For example, if you have breakfast at 6 AM, dinner would be moved to 2 PM, which is why this method is also known as 'not eating after noon'. If you start eating at 8 AM, you should stop eating after 4 PM. This fasting method is difficult for many people to follow due to the length of the fasting period.

The fourth mode is alternate day intermittent fasting, which involves fasting every other day, consuming no solid food on fasting days, limiting calories to less than 500, or reducing food intake to between 25% and 30% of usual amounts. Scientific studies have shown that alternate day intermittent fasting has positive effects on weight loss and cardiovascular health in overweight adults. However, maintaining this type of fasting long-term can be challenging.

Chen Chaogang indicated that intermittent fasting can be adopted for a period, but it is not recommended for long-term use.

Weight loss should be pursued in a healthy and comfortable living state.

'This Chinese New Year, we had a person come in for a follow-up visit who not only did not gain weight but lost 4 kilograms. How did he achieve this? First, he eliminated animal skins such as goose, duck, and chicken, both when eating at home and dining out; second, during the festival, he also ate whole grains; and third, he strictly followed the advice I gave for eating. Even though the portions were quite generous and he ate until satisfied, he still managed to lose weight.' Chen Chaogang noted that the hospital is conducting research and, therefore, recruited 60 volunteers before the New Year. Based on their personal situations, they were given a dietary plan. These days, several people have come to weigh themselves and noticed that by following the plan, they have lost weight. However, a man who has the habit of not having breakfast has gained weight. Analyzing his case, it could be due to the fact that by frequently skipping breakfast, he ended up eating more at lunch and dinner.

'Whenever I help overweight individuals, I emphasize that scientific weight loss must follow a three plus one approach. First, strict control of oil is essential; the amount of oil for cooking should be limited to one tablespoon (approximately 10 grams) per person per meal, with a maximum of three tablespoons a day. It is also necessary to strictly control the oil present in processed foods, such as fried doughnuts, cream cakes, and bread, which contain large amounts of oil. Additionally, one should moderate the intake of meat, dairy, eggs, and all fatty foods. Secondly, increase vegetable consumption. Currently, most overweight patients we treat at the hospital do not consume enough vegetables. It is recommended to eat first two types of oil-free vegetables, each weighing 200 grams; one should be leafy, such as spinach and green leaf vegetables, and the other non-leafy, such as zucchini, squash, and eggplants. Only after consuming these vegetables can one eat anything else. Thirdly, dinner should be moved forward as much as possible, preferably before six or six-thirty. Additionally, it is important to increase the level of physical activity.' He laughs and comments that he checks his phone every night before sleeping to confirm that he has walked at least ten thousand steps.

Chen Chaogang has made it clear to journalists on several occasions: 'Weight loss should be pursued in a healthy and comfortable living state, without affecting work or mood, otherwise it will be difficult to maintain. One should not starve; eat enough food.' In summary, this means that breakfast should not be skipped, enough should be eaten at lunch, and dinner should be as early as possible. Some say that eating after seven o'clock in the evening counts as a 'snack', and Chen Chaogang believes that this statement has some validity, so it should be attempted to reduce food intake after that hour. But what should 'working people' who finish their workday late do? He suggests that they try to eat earlier, or immediately consume some carbohydrates and dairy products after finishing, along with fruits, and that at dinner only low-oil vegetables and soy products should be taken. One can also consider increasing time and amount of activity after dinner.

Eliminating carbohydrates from the diet to lose weight is a mistake.

Many celebrities say that carbohydrates are high in energy and that they have not eaten rice in years. In response to this claim, Chen Chaogang stated: 'What influences weight is total energy intake, not carbohydrates. Fats have high energy and are present in various foods, making them more difficult to control, so attention and regulation are necessary.' On the contrary, he suggests that people who want to lose weight should eat a bowl of rice at noon and in the evening, recommending that tall individuals consume 100 grams (of uncooked rice), those of medium height 75 grams, and those shorter 50 grams.

In addition, a balanced diet is also very important. Fruits and vegetables are not only low in calories, but the dietary fibers they contain create a feeling of fullness, help reduce fat intake, and are rich in many nutrients. Therefore, it is crucial to ensure adequate consumption.

Additionally, Chen Chaogang added that though intermittent fasting may be beneficial for physical and mental health, it is not recommended for patients with hypertension, diabetes, cardiovascular diseases, elevated uric acid, gout, or menstrual disorders, as it may induce abnormal metabolism in the body. Therefore, it is advisable to consult a doctor before undertaking this type of fasting.

Finally, it is also important to note that one should not seek excessively rapid weight loss. Chen Chaogang points out that normal and scientific weight loss is between 2 and 4 kilograms per month. For example, a certain celebrity who has recently been much talked about lost 100 pounds in a year, averaging about 8 pounds per month, which, numerically speaking, seems reasonable. However, such considerable weight loss each month must be conducted under the supervision of a doctor and should not be blindly imitated.

Content comes from: Guangdong Provincial Association of Science and Technology.

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