Although oils like olive and coconut are far better choices for your heart than butter, these oils too are extremely fat and calorie-dense. If you struggle to lose or maintain weight, omitting the use of oils will make a huge impact on your fat intake that you'll never miss.
Did you know that it's simple and effective to cook without using oils?
You will never count calories ever again once a whole foods plant-based lifestyle is adopted. Leaving the oils behind is a large element of why. For an interesting read on "Is Coconut Oil Bad for You", check out the discussion on Nutritionfacts.org.