Master the "Ten Tennis Balls" Principle for a Balanced Diet
Recently, some American experts proposed a principle for people over 40 to manage their daily dietary structure, known as the "Ten Tennis Balls" principle.
What is the "Ten Tennis Balls" principle? It means dividing your daily food intake into portions the size of ten tennis balls: "no more than one tennis ball of meat," "equivalent to two tennis balls of staple foods," "ensure three tennis balls of fruit," and "at least four tennis balls of vegetables." This dietary distribution method is scientific and rational, ensuring a balanced intake of protein, fat, carbohydrates, vitamins, trace elements, and other nutrients, while also preventing overeating.
"No more than one tennis ball of meat" The total amount of meat consumed in a day should not exceed the size of one tennis ball, including all types of meat such as pork, beef, lamb, chicken, duck, and fish. Meat is high in calories; eating too much makes it difficult to burn off, leading to obesity and being overweight. For instance, the average calorie content of red meat is over 200 kcal, ten times that of vegetables. However, it's also not advisable to cut out meat completely, as it is detrimental to health. The human body needs to supplement with Vitamin B12, which is primarily sourced from animal foods like liver, lean meat, eggs, and fish/shrimp. Most plant-based foods do not contain Vitamin B12 or contain very little. A deficiency in Vitamin B12 can lead to numerous problems, such as megaloblastic anemia or hyperhomocysteinemia. The latter condition is a risk factor for cardiovascular diseases in itself. Even without eating meat, cardiovascular and cerebrovascular diseases can still occur, so an all-vegetarian diet is not necessarily better.
"Equivalent to two tennis balls of staple foods" This is roughly equivalent to 200-250 grams. Having more or less is not appropriate. It is incorrect for some people to completely avoid staple foods. Staple foods are the main source of carbohydrates. During digestion...