One of the connections between fat and heart disease is that consuming fats can affect a person's cholesterol levels, a risk factor in developing heart disease. Another connection is that a person who is overweight has a higher risk for heart disease. The risk particularly high when a person has a high amount of visceral fat, or fat around the belly. Being overweight can also cause strain to the heart and lead to other health problems. Since fat has such an effect on heart disease and health, some recommend that overweight people reduce the amount of fat they eat and seek to remain at a healthy weight.
For those who are overweight, the connection between visceral fat and heart disease is an important one. Unlike subcutaneous fat, the fat that lies underneath the skin, visceral fat lies deep in between the abdominal organs. It is often the fat that gives a person an "apple shape." Those who have large amounts of visceral fat around their midsection are at a higher risk of developing heart disease, including heart attacks and chronic heart failure.
Another connection between fat and heart disease comes in the form of the type of fat a person eats. Certain fats are good for the heart and body and can help a person lower his or her cholesterol levels. Others can lead to higher cholesterol levels. There are three types of fats that are of concern when it comes to the connection between fat and heart disease: trans fats, saturated fats, and unsaturated fats. Saturated fats and trans fats can have a negative impact on the heart, while unsaturated fats can have a positive one.
The connection between an unsaturated fat and heart disease is a good one: unsaturated fats can help lower cholesterol. These, like all fats, are made from carbon, hydrogen, and oxygen, but unsaturated fats have at least one double bond between the carbon atoms, which means they are able to hold on to more hydrogen than they currently have. As a result, they are usually liquid at room temperature and can go rancid easily. There are two types of unsaturated fat: monounsaturated, which has one double bond, and polyunsaturated, which has more than one double bond. Olive oil, sesame, canola, and avocadoes are some examples of unsaturated fat.
Saturated fats are those fats that do not have a place for a hydrogen molecule to bind to; they are already saturated with hydrogen. These fats are commonly found in animal fat but also exist in certain plant oils like coconut oil and palm kernel oil. They are often solid at room temperature. Saturated fats have been implicated as a contributor to increased cholesterol levels. There is some debate about whether this fat really increases cholesterol levels or if there is another culprit, but most experts agree it is best to limit the intake of this type of fat.
Trans fats are unsaturated fats that have gone through processing to saturate them. The hydrogenation process adds hydrogen to the fat to make it solid and more stable at room temperature. This can increase the shelf life of certain products. It also raises so-called bad cholesterol (low-density lipoprotein or LDL) and lowers so-called good cholesterol (high-density lipoprotein or DHL). This fat can be found in many foods such as baked goods and margarine.