I was born with Phenylketonuria (PKU - read about it here). This means, for the first 15 years of my life, I was on a strict, very low protein diet. Until my mid-teens, I hadn't eaten any meat, fish, milk, eggs or bread and could only eat limited quantities of potatoes, mushrooms, beans, etc. I took (very horrible-tasting) supplements and visited the dietician at least twice a year.
These days, the recommendation is that people with PKU remain on this diet their whole lives. As I said, I started a normal diet at 15 and have eaten normally since. I often consider returning to my diet in the hopes this improves my life. Side effects of PHe build up in the body are severe, but I have lived with them my whole life - though it does seem as I get older that these are becoming worse. It is not quite that simple, though. While I was on my diet, my physique was, at most, a stocky 5'7". After a year or so of eating a normal diet, my height increased to the comparatively lofty 6'3" that I enjoy today. Clearly, the increase coming off the very restrictive diet did me some good.
That said, I am still very wary of getting caught up in the body building/protein frenzy craze as part of my health and fitness journey - simply because I know that, for me, there is much more at stake.
Regardless, I'm not going to allow that to compromise my current health kick. I'm 48 now. It is time I got this body into proper shape.