While I am here I may as well mention that the extra weight came off within days, so I guess it was salt or whatever causing an increase mainly in water more than anything else. Nevertheless I would not liked to have carried on doing this!
You can see this on the graph in my original post. It is a live image, so gets updated when I add a weight.
It is good to know my weight is fairly stable.
Next stage, fitness I think. It would be good now to get into shape as well, though I may do a fast in the new year.