Digimon Frontier, Accel World Recommendations
The "worlds" in both Anime share similar elements to them despite having different concepts. There is also the element of getting to come home and becoming a better person by fighting in these worlds to survive and the characters grow in maturity over time.
The concept of becoming a digital form of a new being/avatar is a presented theme in both series as the main characters are able to venture into another world through technology.
From both series, the setting takes place in a digital like realm where fiction crosses over with reality. Make no mistake as the threat of pain in this other world is real and there are consequences for making the wrong choices.
Both series adapts science fiction themes and the main male protagonists are determined to achieve their ambitions.
Both series also have drama, comedy, and a small cast of characters involved in this other world.
Both have overweight main characters.