What would be a high food energy sweetener?

I understand its defined as calories in diet world, so how would I get a sweet flavor with a high calorie intake. Im skinny and tend to skip eating so Im looking for 1 of many foods to just get the most out of what I do eat.
Thank you, Spindoctor izzy, for not answering my question and assuming im an idiot. Im looking for my sugar, I dont need to be told how to eat.