I have completely changed my body (well, I am still an hourglass)
I have always exercised a lot. I have always swam about 2 hours a week, and walked about 90 minutes a day, with frequent walking holidays doing 10-15 miles a day. This alone did not change my body
About 18 months ago I started doing Body Pump. You do have to go for it though and progress your weights. I often hit failure. I notice women who have been doing it the same amount of time as me, they only have tiny weights on the barbell and they are not changing shape.
Every week I do 1x body pump heavy, 1x normal body pump, athletic pilates and reformer pilates. As I said above, I keep increasing my weights to failure point.
I have noticed a lot of changes in my body. I used to have really fat arms, now, they are normal sized but look mostly muscular/toned with a very small amount of bingo wings, my shoulders look defined. I have a pert and curvy bottom, small waist, my legs are lean and toned, just a tiny bit of wobble on my inner thighs, really subtle cellulite if I really try to jiggle my leg.
I am 50 years old, and spent the summer in little shorts and vest, looking toned and tanned and feeling really body confident.
Change is possible, but you really have to put the work in. I work really hard at my exercise!
I avoid UPFs 98% of the time, cook pretty much everything from scratch except for bread products that I only eat occasionally e.g. some wraps, the odd sourdough loaf, bit of a bagel habit. I eat plenty of protein but I'm not tracking.
I can now do full push ups! I could never do full push ups all my life, but now at age 50, I can do it for the first time