When you make muffins, one way to control calories and fat is by keeping them to a reasonable size, unlike those giant muffins you might buy at the store.
You can also try a few other things. In this old family recipe for sour cream muffins, I reduced the calories and fat by using egg substitute instead of real eggs, and light sour cream instead of full-fat sour cream. I also omitted the original butter-rich streusel and sprinkled the muffins with poppy seeds.
These little adjustments cut the fat of the original recipe in half and the calories almost by one-third without sacrificing any flavor.