That depends on what/how you're cooking with butter. Butter is pretty much all fat and while some fats are necessary, they do need to be limited. You might try cooking with some of the healthier oils, such as coconut oil, safflower, sunflower, sesame oils. Each one has its own special taste and most can be used in cooking/baking just like butter.
Chefs often mix olive oil with a little butter in cooking. But olive oil is a low-heat oil.