All fats, regardless of source, have nine calories per gram. There are four main types:
Monounsaturated fats:
This type of fat is a liquid at room temperature and can harden when chilled. It’s a heart-healthy fat that can lower cholesterol and lower the risk of heart disease and stroke.
Polyunsaturated fats (omega-3s included):
Like monounsaturated fats, these fats start off as liquids but start to congeal when cooled. Olive oil is an example of a polyunsaturated fat.
Rans fats:
These are liquid fats that are made solid through hydrogenation. They are found in fried foods, baked goods, and processed snack foods. Trans fats are terrible for the heart and in 2015, the FDA announced that it will ban the use of these fats starting in 2018 (giving manufacturers a chance to get their products to speed).
Saturated fats:
These are solid at room temperature and are found in meat, butter, coconut oil, and palm oil. This is typically thought to be a bad fat, but the evidence is mixed, so don’t dismiss it out of hand just yet.