In reply to Gordonbp:
I'm 76 and was 12 stone 5 lbs (ht 5'10") at the beginning of lockdown.
I walk most days in the country and Downs for between 1 and 6 hours at a time.
I have a bowl of cornflakes and milk first thing in the morning, and when walking I have coffee, a small slice of malt bread, and a banana mid morning, and sandwiches (4 slices with cheese and pickle) and a small orange for lunch. In the evening I have a main meal of mainly a chicken or fish based meal with rice or potato and one veg (sweetheart cabbage or frozen peas). I sometimes have a pudding of yoghurt or ice cream.
I tend not to snack between meals, although I allow myself 1 or, sometimes, 2 glasses of red wine with nibbles such as peanuts or Bombay mix as a treat whilst watching TV in the evening.
I am finding this regime healthy, and have lost nearly a stone since the start of lockdown, and I think the main reasons are the regular walking, not meeting friends for cappuccinos during the day, never eating out now, and a reduction in alcohol intake. I am feeling very fit and feel better generally than I have for years by the enforced lockdown.
I have also noticed a significant drop in my monthly spending, which is a bonus.
PS I'm sure I would loose even more weight if I cut out the wine and nibbles, and puddings, completely, but Hell, you need some treats in life I feel that I've got the balance right, and if the weight starts to creep up, the puddings will be the first to go.
Good advice from Marsbar about making walks more interesting if you have an App or GPS device to plot your routes. I spend a lot of time now studying the OS sheets for my area and working out routes along "new" or or amended footpaths. Putting it to the test the next day is good for your navigation and is a lot of fun.
Tip - unless you have access to moorland or hills it's advisable to carry pruning shears, and a stinging nettle bashing stick (I walk in shorts) because many of the lesser used paths are becoming overgrown. Again, more fun in re-opening them!