my Mica is a bit fussy. She has gone from science diet to eukanuba or iams to now working into eva innova - since I read this is good on this forum. She also likes the raw meat diet (little silver doller sized 1/2 high meat discs in venison/turkey,chicken/and yet to try other variety) which will be one meat disc per meal since they are a little pricey, along with some pedigree packets variety (about a tablespoon) - and sometimes that dog gravy, too - all mixed together. I will put a few teaspoons of yogurt on top in the morning sometimes, and than sometimes I also add cooked rice. It tends to vary every meal - no set formulae. I mean, I really prepare her meal and work to get her to eat. But she does wait patiently while I prepare it, most of the time, too. If she doesn't immediately eat - (sometimes) I pick the food up, put a celaphane (spelling?) wrap on top of the dog dish and than try feed it at the end of the day. Usually she does this. She has gone as long as a full day without eating so far. She can be picky. Like today she ate only the eva innova kibbles in the morning. She didn't want anything to do with the other moist food until evening. Sometimes I eat something along with her eating time, too - I don't know if this has to do with pack animal communication but may be so - since she follows me everywhere in the place where I live. She will also share a ball or a bone cooked and fished out from a soup and flavored with her favorite cocker spaniel friend, at her place. But the cocker is a good dog. She likes treats. All kinds of variety there. So I can never be sure that if I set this food down, this is the always what she will eat source of flavor. Sometimes I try to think that if I were a wild dog, since she appears to be just shy of a wild creature - what would be the yummy wild treat to eat this morning for breakfast? That seems to do the trick for hunger variety. But than, she is a wonderful little B - a creature all unto herself. 
i should add that, as long as the hips/knees are good or excellent, I don't mind my seniors carrying a few extra pounds. years ago we had a lab who was dysplastic and I was very careful she NEVER carried extra weight. Jet's ideal weight is about 26 and he maybe a few pounds overweight. It's a little more difficult for the seniors to bounce back from any sort of illness and Jet's hips were OFA'd Good, so I don't worry about a little extra.
The veggies will add fiber to the dogs' meals and help fill them up. I would not use canned as it tends to be high in sodium. If they don't like the veggies, you may want to try to cook them in a little chicken broth to help the flavor. or you can decide if they aren't hungry enough to eat the veggies, they aren't really hungry.
My house is colder in the winter, so I tend to feed the b's 1/3-1/2 a cup 2x a day. And I tend to train more during the nicer days, so Z gets very little at meal time as I have to watch that. (I use lots of treats during training.)
But really, I would not switch to a different food just to reduce the weight. For Z I also usually use a puzzle toy for feeding her meals so it lasts longer.
For comparison, Zest!'s official measurements (for AKC agility) were 15.88 and 16 inches and I think she looks best at 20 pounds.
