I like to hike, and have been surprised to see people who are outright obese climbing mountains. I have also seen really old people making it to the top. However, I am reminded of the saying that there are "old pilots, and bold pilots, but no old bold pilots." I have yet to see any old obese hikers!
Then you should see the pictures of my hikes on Facebook :>)
I am an old (56) overweight (245) hiker! Went to the 8600 ft level on Mt Rainier in July.