No, it doesn't work that way.
You can transfer matter into energy and in theory energy into matter.
Matter suddenly weighing less makes no sense at all.
Tuppence said that it is not things we see like tables that change in weight, but electrons. Perhaps she doesn't realise that there are billions and billions of electrons in a table, so it is the table changing in weight.
The whole concept is too ridiculous for words.
Light travels slower, so I am getting heavier???
Perhaps that is even the source of the weightproblems in the western countries nowadays??