Rumors] Many people have heard the rumor that “you can eat more egg whites, but not more egg yolks, and you can only eat a maximum of one per day”, on the grounds that its cholesterol content is particularly high and eating too much is harmful to your health. Is this widely circulated statement reliable? According to experts, the reason why you should not eat more than one egg yolk per day is that an egg yolk contains 200 mg of cholesterol, and the human body should not consume more than 300 mg of cholesterol per day, so from a nutritional point of view, one egg yolk per day is enough. If you consume too much, you will have too much cholesterol in your body, which will build up in the walls of your blood vessels and induce cardiovascular disease. Indeed, scientific research over the past decades has been suggesting that there is a direct causal relationship between dietary cholesterol and the occurrence of cardiovascular disease, and for a longer period of time, the nutritional, medical, and scientific communities have been in agreement: to reduce the incidence of cardiovascular disease, we must limit the intake of dietary cholesterol. Thus, since 1977, the dietary guidelines of the U.S. Department of Agriculture and the Center for Nutrition Policy of the Department of Health for the general public have been to reduce the use of eggs, butter, and other foods high in cholesterol and to limit cholesterol intake to no more than 300 mg per day. This recommendation was later incorporated into the Dietary Guidelines for United States Residents. As a result, this concept was also accepted and introduced in the domestic nutritional community, leading to the above-mentioned advice from doctors to some patients: to eat a low-fat diet, eat as many egg whites as you want and just one egg yolk per day, and throw away the excess. However, this statement was denied with the release of the new edition of the Dietary Guidelines for Americans on January 9 of this year, which vindicates the previous misconception that cholesterol, of course, includes egg yolks, and removes the daily limit on cholesterol intake. The expert committee for the U.S. Dietary Guidelines released a 572-page scientific report that states on page 91: “The previous Dietary Guidelines recommended that daily cholesterol intake should not exceed 300 mg. In the new Dietary Guidelines, we will no longer follow this recommendation because new scientific evidence shows that there is no clear relationship between dietary cholesterol and serum cholesterol levels, as reported by the American Heart Association and the American Cardiovascular Society. Whether cholesterol is overconsumed is no longer a concern.” After the release of this report, there was an outcry; have we been wrong for the past few decades? In response to this shift, experts have explained that past studies have found that only 15% of serum cholesterol comes from the diet, while the remaining 85% comes from synthesis in the liver. The human body has a powerful feedback regulation system that regulates the amount of cholesterol consumed to regulate the amount of synthesis in its own liver, thus ensuring that intracellular cholesterol is maintained at a relatively stable level. Therefore, dietary cholesterol intake does not have a significant effect on serum cholesterol levels. However, from a nutritional point of view, it is not recommended to have a burger or fries. In addition, there is a misconception that “LDL cholesterol, commonly known as ‘bad cholesterol’, is deposited on the walls of blood vessels and forms atherosclerotic plaques”. In fact, only the small, dense, and oxidized LDL is the real “bad cholesterol”. They get stuck in the blood vessel wall, induce local inflammatory reaction, and are engulfed by macrophages to form foam cells and adhere to the blood vessel wall, which gradually form blood vessel plaque and make the blood vessel narrow or even blocked. A high-carbohydrate diet stimulates insulin secretion and accelerates the conversion of macrophages to foam cells; excess glycogen is converted to triglycerides in the body and contributes to the formation of more small, dense and truly bad LDL, while a diet of polyunsaturated fatty acids increases HDL cholesterol, often referred to as “good cholesterol”. HDL can effectively clean up the LDL deposited on the walls of blood vessels, playing the role of “vascular scavenger”. In the past few decades, due to the dietary guidelines on daily cholesterol intake, people have switched to eating more carbohydrates while keeping the total daily diet unchanged, and the food processing industry has been using more artificially added sugar, salt and other flavorings to enhance the taste of food in order to better suit human tastes and preferences. Therefore, the dietary guidelines decided to remove the dietary restrictions on cholesterol, but also contains the hope that people will shift the focus from cholesterol to a high-sugar diet, from limiting cholesterol to limiting the use of various added sugars, in order to make a more balanced diet, so as to increase polyunsaturated fatty acids and promote the level of “good cholesterol”. So, how many egg yolks can be eaten per day? Experts believe that while the latest dietary guidelines have removed the cholesterol restrictions, other dietary principles have not changed. According to the dietary guidelines, it is best to consume no more than 10 percent of total calories of saturated fatty acids per day. In layman’s terms, if you are not fat, then you can safely eat five eggs a day, including the yolk.