Ah! The never ending question of gaining weight, and how to lose it.
I'm 68 now, but at the peak of my fitness when I was walking almost every weekend & holiday, including long days in the Lake District or a few Munros a day I was about 76 to 77 Kg
Then a few things happened fairly close together - marriage & family life; rheumatoid arthritis, so although I can still do some walking & backpacking, I can no longer do the long hard days; diabetes, which makes it difficult to lose weight as you keep going into hypo if you cut down on food.
All this meant that although there were fluctuations, on Ist January 2018 I was 94,2kg - not good
So I made a renewed effort; I was able to do more day walks now that I'm retired, and paying much more attention to diet & blood sugar testing.
Today I'm 85,9kg; I know I will probably not get as low as 77 again, but I'm aiming for about 82kg
Both weight gain and weight loss have a combined or rolling effect - the more exercise and sensible eating you do, the more weight you lose, and so the more you are able to exercise and have the motivation or enthusiasm to eat properly, and so the more weight you lose, and so on
The converse is true. If you are overweight and unfit you are less inclined to do any exercise and more likely to sit around eating, so the more weight you put on......
I've tried swimming but never managed to learn; I've been to a gym a few times and not enjoyed it, so the only real exercise I do is walking
However, as my wife has pointed out on more than one occasion, I have always wanted to go for A PROPER WALK, meaning something reasonably long & hilly in the Peak or Lake District. If I can't do that I haven't done anything
It's only really in the past few months that I have made myself just get out anywhere, like walking into the town centre or around lower level paths & lanes. I still have to persuade myself to do this, yet I enjoy it when I do it
I was brought up on traditional hiking gear - wool, tweed breeches, big leather boots, and all the rest of it. Something that helped me do more walking, and to enjoy it was the change to lightweight stuff - trail shoes, synthetic sports pants; very light waterproofs, and so on.
Thus, even when in my overweight & unfit state I felt more comfortable and agile.