Flu season is coming at us fast. Don’t lie, whenever someone sneezes close enough to you that you feel a breeze, you wince and wonder how long it will be until you catch the bug. But we’re here to help. “Immune system soldiers need good, consistent nourishment,” says Jennifer McDaniel, R.D.N., a food and nutrition expert. Here are seven essential foods that you should fill your plate with during cooler-weather months to help your immune system work at its optimum level.