Fats are also known as lipids and are very calorie dense, with twice the calories per gram as protein or carbohydrates. Saturated fats occur naturally in many foods, especially animal sources such as meat and dairy products. These fats cause high levels of blood cholesterol, which in turn increases your risk of heart disease and stroke, and it’s recommended that your intake of saturated fats only total 7% of your daily calories.
Unsaturated fats come in two forms, the first being monounsaturated which are liquid at room temperature but begin to solidify at cold temperatures. This type of fat can be found in olives, olive oil, nuts, peanut oil, canola oil and avocados, and actually lowers ‘bad’ cholesterol and maintains ‘good’ cholesterol. The second form of unsaturated fats is called polyunsaturated, and is also liquid at room temperature. These fats can also lower bad cholesterol, but be wary of overdoing it as they can also lower your good cholesterol. You can find polyunsaturated fats in sesame, corn, cottonseed and soybean oils, and, generally, unsaturated fats should make up most of your daily fat intake in the form of olive oil, fish, omega 3 supplements and nuts.
The worst kind of fats is called Trans fats, which are unnatural and didn’t even exist before 1890. An industrial process that adds hydrogen to liquid vegetable oils to make them more solid, and they are even worse for your health than saturated fat as they increase your bad cholesterol and lower your good cholesterol. Avoid Trans fats by forgoing highly processed foods such as biscuits, pizza dough, margarine, chips and ice cream.
The general rule for fat consumption for health purposes is that fat should make up 20-30% of your total daily calories and it should come from fat unsaturated sources. If you are following a diet that is low in carbohydrates, you will have to raise your fats to compensate for the lack of calories and vice versa.