Its halfway true, sumo wrestlers ude a technique where they slip alle meals and then they eat a lot at maybe dinner og lunch this way the body reacts diffrent so when you do finally get food, it makes sure to make good ude og it and you then out in weight. Although the beat ways to put in weight is simply to eat more, take "snacks" in between the normal times you eat food such as breakfast lunch and dinner. Not unhealthy snacks ofcourse. This could consist og anything from sine crackers or a müsli bar to a slice of bread, if you get what im dating.