Health and fitness means a lot to our life, so people find many many ways to have a good health. You should maintain a healthy diet. Healthy foods such as vegetables, fruit, grains, etc., are an important part of keeping my body nutrition at its optimum. Processing fatty and sugary foods don't give the immune-boosting protection that healthier food does. Sugary foods can decrease immune function. Next, you had better drink 2-litter- water a day to provide enough amount of water for your body. Finally, make sure that you get adequate sleep every night, get at least seven to eight hours sleep nightly.