text: what will happen if i only eat once a day? i dont know what will happen :/ if you eat only once a day you are going to lose weight or become anemic. don't play with your body this way. your hurting your body thought you knowing it! you supose to eat at leat 3 meals a day and a snack(if you want) are you trying to starve yourself? think about what you are doing  to yourself.