I was a tall and skinny kid groing up, hit about 15 and broadened out, never needed to worry about weight or exercise until well in my 20s.
As such, i hit a point as i got closer to 30 where my metabolism slowed way down. Gained a bunch of weight, looked like shit, felt like shit.
Around 30ish i started making lifestyle changes.. Quit drinking, stopped eating red meat, heavy fatty foods. For a while i was completely vegan but that only lasted a year.
That was enough to keep me at a good weight for a while, but then it started creeping back up as i got closer to my mid 30s.
At which point i got real serious about exercise. Now, i try to do several hours a week, mostly exercycling..i also do all our yard work. In recent years ive added some weight lifting to the mix. In short, im probably in the best shape of my life, now. I remember, after i finally took the weight off, that thinking "hey! I must be doing something right--- Women are flirting with me, again"
My diet is still pretty good- fortunately i live in a part of the country where its easier to eat better, and ive always liked vegetables. Ive taken up gardening in recent years and have found that not only are things like kale perfectly suited to the colder rainy clime i live in, but thankfully the ever present slugs in this area dont particularly like it, either.
I know lots of people struggle with things like diet and weight. For me, half the battle has been making sure to eat better meals that skew lower on the food chain, and half is exercising religiously.