Scientific intake of meat and eggs: From choosing high-quality protein to the nutritional balance of cooking oils
Vegetables and fruits are closely related to the prevention of cardiovascular disease. They are high in potassium and low in sodium, which helps maintain normal blood pressure. The dietary fiber in vegetables and fruits binds with bile acids in the intestines and is excreted, lowering blood cholesterol levels and helping to prevent atherosclerosis, thus reducing the risk of coronary heart disease. Vegetable and fruit intake is also related to weight control. Vegetables and fruits are high in water content, low in energy density, and large in volume. In weight-loss diets, vegetables and fruits can increase satiety, making it easier for people to accept low-energy meals and achieve weight control.
We need to understand the appropriate intake of meat and eggs. Fish, poultry, and red meat each have their own nutritional characteristics, but they all share the common feature of being high in protein. Lean meat contains approximately 15% to 20% protein, and it's high-quality protein. This means that the amino acid composition of this type of protein is more compatible with the body's needs, resulting in higher utilization. The iron in meat is mostly heme iron, which is absorbed much more efficiently than iron from plant sources. Weight-loss diets should appropriately increase the proportion of energy derived from protein. Completely eliminating meat makes it difficult to increase protein intake. When choosing meat, it's best to opt for more white meat and less red meat.
Red meat is called "red meat," while fish and poultry are called "white meat." Red meat, especially pork, is high in fat, primarily saturated fatty acids, and should be consumed in moderation. Fish is tender, easily digestible, and low in fat, generally between 1% and 3%. Marine fish contain polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which help lower blood lipids and prevent cardiovascular disease, making them ideal for the elderly. Animal organs should not be eaten in large quantities. Animal liver is very high in vitamin A. Consuming a moderate amount of animal liver can compensate for insufficient vitamin A intake in the diet.
Animal organs are also rich in folic acid, vitamin B12, and nutrients such as zinc, copper, and selenium. However, excessive intake of vitamin A can lead to poisoning. If you eat 100 grams of lamb liver once a week, even without considering other sources of vitamin A, your average daily vitamin A intake will be close to or exceed the tolerable upper intake level recommended by the Chinese Nutrition Society. Furthermore, animal organs are high in cholesterol; adults should not consume more than 300 milligrams of cholesterol per day. Therefore, animal organs should not be eaten in large quantities.
It's best to eat no more than one egg per day. The issue of egg consumption continues to be debated, with some people discarding the yolk due to concerns about its high cholesterol content. While it's true that egg yolks contain various vitamins, including B vitamins, vitamin A, vitamin D, vitamin E, and vitamin K, as well as lecithin, they are also high in cholesterol. A medium-sized egg contains approximately 300 milligrams of cholesterol. Regarding the relationship between increased dietary cholesterol intake and elevated blood cholesterol levels, substantial research evidence suggests that most people should limit their daily cholesterol intake to no more than 300 milligrams.
Therefore, it's best to eat no more than one egg per day. If you want to allow for other animal-based foods, or if your blood lipids are already high, you can eat one egg every other day. Choosing the right cooking oil is also important. Cooking oil is a significant source of fat in the diet. It's important to choose the right type of cooking oil. Nutritionists recommend that the daily intake of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids should ideally be in a ratio of approximately 1:1.5:1. However, for the average consumer, it's difficult to strictly adhere to this ratio when choosing cooking oil.
According to the survey, most families prefer to use only one type of oil. Many residents use lard as cooking oil. Lard is high in saturated fatty acids, so if there is already meat in the side dishes, it is best to use less lard when cooking. Commonly used soybean oil and peanut oil provide polyunsaturated fatty acids. Adding tea seed oil or olive oil, which are high in monounsaturated fatty acids, to these oils will make the fatty acid ratio more balanced. Rapeseed oil is high in erucic acid, and a considerable portion of commercially available rapeseed oil has not had erucic acid removed. This type of rapeseed oil is bad for the heart and should be used in combination with other vegetable oils.
It's best to rotate between different types of cooking oil. This allows different fatty acids to complement each other and avoids excessive intake of potentially harmful substances found in certain oils. Commercially available blended oils are a mixture of various vegetable oils; if the proportions are appropriate, they can allow the various fatty acids to work synergistically.