Does using sugar as an alternative to commercial feterlizer work?

No, fertilizer has many ingredients that sugar doesn't even begin to cover.

Regular fertilizing programs give you more nutrients.

Sugar alone does not feed properly like a fertilizer. Also there are a lot of plant specific fertilizers out now that will give your plants more of what each plant that needs help needs nutrition wise.

I have been gardening and studying gardening tips & horticulture for many years and I have never heard of using sugar. I think someone has lead you up the garden path with that advice. If you do not wish to use chemicals or fertilisers simply buy (or make) some organic compost.

I have never heard of this! I also know that sugar attracts ants - never would I do that!