I'm 30+ and when I was young, I was really really skinny. Then I started working in the very unhealthy IT business.
Long hours. No exercise whatsoever. Lotsa carbs to please the brain. I got very fat, very quickly.
I still work in the IT business.
Long hours. No exercise whatsoever. A lot of fat. And I'm quite thin and I have more energy than ever.
Cut the sugar, eat fat, get skinny. It works.