Boxing/Losing Weight too fast

First of all, you've only been doing this for a year, and it sounds like you've made some good progress during that time. But real maturity in combat sports (strength, speed, endurance, bodyfat %, etc.) takes a lot longer than 1 year to achieve. My first question would be, are you now competitive or do you plan on competing in the future, or is this just for health, fitness and personal achievment? While it's generally true that excess fat is non-fuctioning "cargo" you'll have to carry around the ring for however many rounds, I've seen some really good fighters who weren't "ripped" to the bone, but still had very respectable levels of speed, strength and endurance. If you're gonna be competitive, then yes, carrying excess bodyfat will put you at a disadvantage because you'll be carrying MORE FAT (non-functional), and LESS MUSCLE (functional) than your opponent who weighs in at the exact same weight as you do! If you're not planning on competing, then the higher bodyfat level (15% is really not that bad, BTW) is only an issue if it's a "thorn in your side" on an aesthetic level. This is completely understandable. I've been involved in Muay Thai and MMA for about 10 years, but my roots in bodybuilding always show up when I not only want to punch the hardest and fastest, I want to look good doing it!