If you wish to make this low fat use onion powder instead of onion salt.
Instead of one cup veg oil use 1/2 cup veg oil and 1/2 cup water. I had a co-worker who did this and just used water and no oil and liked it this way.
Also you can use something like Splenda instead of suger.
You can also try a diffrent type of oil instead of veg oil for example olive oil.