The facts about fat
There are numerous types of fat. Your body makes its own fat from taking in excess calories. Some fats are found in foods from plants and animals and are known as dietary fat. Dietary fat is a macronutrient that provides energy for your body. Fat is essential to your health because it supports a number of your body's functions. Some vitamins, for instance, must have fat to dissolve and nourish your body.
But there is a dark side to fat. Fat is high in calories and small amounts can add up quickly. If you eat more calories than you need, you will gain weight. Excess weight is linked to poor health.
The concern with some types of dietary fat (and their cousin cholesterol) is that they are thought to play a role in cardiovascular disease and type 2 diabetes. Dietary fat also may have a role in other diseases, including obesity and cancer.
Research about the possible harms and benefits of dietary fat is always evolving. And a growing body of research suggests that when it comes to dietary fat, you should focus on eating healthy fats and avoiding unhealthy fats. Simply stated, fat is made up of varying amounts of fatty acids. It's the type and amount of fatty acid found in food that determines the effect of the fat on your health.
Harmful dietary fat
There are two main types of potentially harmful dietary fat — fat that is mostly saturated and fat that contains trans fat:
- Saturated fat. This is a type of fat that comes mainly from animal sources of food, such as red meat, poultry and full-fat dairy products. Saturated fat raises total blood cholesterol levels and low-density lipoprotein (LDL) cholesterol levels, which can increase your risk of cardiovascular disease. Saturated fat may also increase your risk of type 2 diabetes.
- Trans fat. This is a type of fat that occurs naturally in some foods in small amounts. But most trans fats are made from oils through a food processing method called partial hydrogenation. By partially hydrogenating oils, they become easier to cook with and less likely to spoil than do naturally occurring oils. Research studies show that these partially hydrogenated trans fats can increase unhealthy LDL cholesterol and lower healthy high-density lipoprotein (HDL) cholesterol. This can increase your risk of cardiovascular disease.
Healthier dietary fatThe types of potentially helpful dietary fat are mostly unsaturated:
- Monounsaturated fat. This is a type of fat found in a variety of foods and oils. Studies show that eating foods rich in monounsaturated fats (MUFAs) improves blood cholesterol levels, which can decrease your risk of heart disease. Research also shows that MUFAs may benefit insulin levels and blood sugar control, which can be especially helpful if you have type 2 diabetes.
- Polyunsaturated fat. This is a type of fat found mostly in plant-based foods and oils. Evidence shows that eating foods rich in polyunsaturated fats (PUFAs) improves blood cholesterol levels, which can decrease your risk of heart disease. PUFAs may also help decrease the risk of type 2 diabetes.
- Omega-3 fatty acids. One type of polyunsaturated fat is made up of mainly omega-3 fatty acids and may be especially beneficial to your heart. Omega-3, found in some types of fatty fish, appears to decrease the risk of coronary artery disease. It may also protect against irregular heartbeats and help lower blood pressure levels. There are plant sources of omega-3 fatty acids. However, the body doesn't convert it and use it as well as omega-3 from fish.