May any fitness expert answer my question, please?

One here ago my roomate and I were quite overweight (both around 185 cm x 110 kg) and having the same age and similar bodies we started the same diet and exercising schedule. To my surprise, though, our results are quite different. While I got thin, he is still a little chubby, but, on the other hand, he got more muscular than me. Why this has happened?
May any fitness expert answer my question, please?
Post Opinion