It isn’t just the weight. A lot of people change drastically as they get older. I know some people who graduated from high school with me 47 years ago, and they are unrecognizable from those kids of 1975. I am too. Letting oneself go also makes a difference, even without the passage of decades. I knew a girl from high school who was very healthily-built and was always well-groomed. It must have taken her some time to get ready in the morning. I ran into her a couple of years out of high school. She had gotten married, put on weight, and really didn’t worry so much about her hair or clothing anymore. Seeing someone like that who had changed so much by her early twenties was more shocking.
Had a friend who married his very beautiful high school sweetheart when both were in their early 20s. By 30, both looked like dumplings with legs....thick legs. Don’t know if they were happy but dang! At 18 she could take your breath away. At 28...I wouldn’t have recognized her if we met on the street.
One thing is once you reach 50, you really don’t need to eat all that much, you could probably easily get by on 1000 calories a day without going into starvation mode, provided you get in the nutrients.