Aye Michael, I believe you are correct.
I have some degree of food management going already (as you probably know), but I would need to fine tune this to get motivation up a little I think.
I do think it could help with training, Leroy could use a little more incentive to allow me to lift him, and Stitch might start considering the harness again if Im lucky ^^.
At the moment, I am keeping the birds stable at a weight were I know they are probably a few grams over their baseline. I got weight data for the birds that go more than a year back though, so I know they could safely lose at least 10g for Stitch, and about 15g for Leroy.
At the moment they are sitting at around 190 for my green fluff ball, and 245-250 for the blue one

.
I totally agree that food management is an important aspect to parrot keeping, I saw that discussion in your blog area, and I think the important thing to realise is that food management isnt intended to starve a bird, but rather keep them at a healthy weight.
Both my birds are as Ive said food managed, but kept at a weight that is probably a little on the chubby side atm

. Might be time to tweak it a little bit!