I cannot see why being confined to home and locality should cause weight problems. Exercise is not limited to an hour and you can walk a brisk three miles in that time anyway. There are plenty of exercise classes online and many people have gardens that need looking after. I appreciate some people are disabled, but the chances are that many of them will not get out a lot normally.
As for eating, as a retired person I haven't been out of the house all day every day for a long time and am quite used to being at home and eating a normal diet without feeling any need to snack.
Far from being in danger of putting weight on, being stuck at home means you have complete control of what you are eating for at least three months, no meals out, visits to friends and family outings etc. You can start a healthy eating plan and stick with it. By the end of the three months you could be several stone lighter and completely adjusted t a better healthier way of eating.
I think it is time we started seeing people who feel a constant need to stuff food in their mouths as unnormal and those who don't as normal, instead of the reverse where anyone who eats normally is considered odd and only those who eat constantly are considered normal.