If your child's weight is within normal limits for his age, stop worrying. He is getting what he needs to maintain his weight and grow appropriately. However, if his doctor says he's not growing well for his age, you have to get creative.
Often, parents are confused when toddlers don't seem to be eating as much as they did a few months back. But it's not that they're eating less but actually snacking more and getting their energy that way. A 2-year-old boy has better things to do with his time, and stopping to sit and eat may be considered an inconvenience. So I would suggest increasing your son's activity to help him burn off calories and develop an appetite, and to offer mini meals six times a day instead of trying to get him to eat one big meal three times a day. You will probably find he's eating more than you thought.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.