You are what you eat—but never more so than when you’re sick or injured. You may crave comfort foods, such as toast and jam or macaroni and cheese, when you aren’t feeling well.

But some of these foods actually can work against you and prolong your illness. Make these smart food choices…

Choose healthful fats in healthful amounts.You should always opt for healthful fats, especially when you are recovering from an injury or illness. Foods high in unhealthful saturated fat, such as beef and hard cheeses, have been found to inhibit the immune system and prolong recovery time. Best: A general rule of thumb (even when you’re not sick) is to consume about 25% to 30% of daily calories from healthful fats, such as monounsaturated fat (olive oil, avocado, peanut butter) and polyunsaturated fat (sunflower and corn oils, salmon, walnuts). Consume very little saturated fat, such as that found in whole milk, red meat and hard cheese. It also helps to eat less fat. A landmark Tufts University study found that a lower fat diet (28% of calories from fat, as opposed to a more typical American diet of 38% from fat) increased the function of T cells, which fight against viruses and bacterial infections.

Eat whole fruit. Drinking orange juice (or any type of fruit juice) is not good for you, especially when you’re sick. These juices are high in sugar and low in fiber, causing a rise in blood sugar that can lead to inflammation and weaken the immune response. While juice with pulp is better for you than juice without pulp (and you can dilute fruit juice with water to decrease the sugar), you get more fiber from eating the whole fruit, and this fiber reduces the spike in blood sugar.

Reduce refined carbohydrates and sugar. Refined carbohydrates, such as white pasta, white rice and white bread, trigger inflammation in the body. Your immune system must work to fight inflammation, leaving it with less energy for fighting off sickness. Also, bacteria thrive on sugar, possibly exacerbating an infection. When you are recovering from injury or illness, just say no to refined grains and sugar!