I seem to remember a Recipe for this, when I worked making up Menu's for a Diet Group, all food was suitable for diabetics, A cornflour paste (You could also use arrowroot) was made, which then was cooked over a Double boiler, to make a clear honey consistency, artificiial liquid sweetener was added, as was the juice of two lemons and the rind of one, grated really finely.
It was cooked to allow the Lemon to infuse, cooled. then placed in fridge. It would be possible to make richer, by addition of a small egg before the mix was heated.
Obviously it lacks some of the taste of its traditional counterpart, but it was good as a spread.
Also a Lisbon or Franco Lemon gives a better taste.