Flu, or influenza, can be eaten in moderation if the patient is not allergic to apples. However, if the patient is allergic to apples, he or she should not eat them. Generally, 100 grams of apples contain 54 kilocalories of energy, 0.2 grams of protein, 13.5 grams of carbohydrates, 1.2 grams of dietary fiber, 4 milligrams of calcium, 4 milligrams of magnesium, 12 milligrams of phosphorus, 119 milligrams of potassium, and 4 milligrams of vitamin C, among other nutrients. If patients with influenza are not allergic to apples, they can eat apples in moderation, which is beneficial to replenish nutrients for the body. If a person with influenza is allergic to apples, he or she usually should not eat apples to prevent allergic reactions such as rashes, itchy skin, diarrhea, and difficulty in breathing after eating apples. Whether patients with influenza can eat apples needs to be judged according to whether they are allergic to apples. Patients are advised to eat light and easy-to-digest food, and to eat less spicy food such as chili and pepper. In addition, patients should ensure enough rest, avoid excessive exertion, drink more hot water, and go to fewer crowded public places.