Food combining is a concept that seems to pop up about once a decade. The basic idea is to eat fruit alone, starches only with starches and fats and proteins only with proteins and fats.
Several diets have promoted this idea: Beverly Hills, Fit for Life, and Marily Henner all promote it. An office temp who helped me out with some filing on Saturday gave me some tracts on it.
I think over the years we have discussed stuff like this on the dope, I would say that the only food combining you really need to be concerned with is making sure that as a vegetarian you combine foods to get complete proteins, and amino acid groups, and making sure you get the right selection of vitamins.
AS to the diet variant of food combining, I put it up there with correcting the acid/base balance of your body dietarily…pretty much hokum.
If you prefer to balance your diet, then work off the food pyramid and play match the foodgroups that way. I try to get 1 protein, 1 veg, 1 fruit and 1 grain/legume in each of my 6 tiny meals. That might translate out to half a deviled egg, half an apple, a large florette of cauliflower and some prezles [a bag of the sourdough mini pretzles from one of those cases of individual packs of pretzels is fantastic for this]