Fat is a chemical compound containing one or more fatty acids essential to keep the body healthy. Along with protein and carbohydrates, it is one of three nutrients that supply calories to the body. Oils are simply liquid fats and the two terms are often used interchangeably.

Dietary fat is an important component of good health. In addition to providing energy, fat delivers essential nutrients such as fat-soluble vitamins and essential fatty acids. Fats and oils also add flavor and texture to foods, as well as increasing a person’s sense of fullness after a meal.

Fats and oils are classified into three major groups depending on their chemical structure: saturated, unsaturated (including polyunsaturated and monounsaturated) and trans fat (chemically altered fats found in manufactured or processed foods). The fats found in foods are almost always a mixture of these groups of fatty acids.

While fats play an important role in good health, they also can damage health when consumed in large amounts. Different types of fats have varying effects upon a person’s health. Polyunsaturated and monounsaturated fatty acids (e.g., fish oils, olive oil) have been shown to have a protective effect on cardiovascular health. Meanwhile, saturated fats and trans fats contribute to health problems in people who consume them at high levels. However, all fats are energy dense, providing 9 calories per gram, more than twice the 4 calories per gram of proteins and carbohydrates.

Eliminating fat completely from one’s diet can lead to a deficiency of essential fatty acids, which can result in negative health consequences. Instead, people are urged to include dietary fats in balance with other nutrients to meet daily energy needs and to achieve a healthy body weight.

In particular, emphasis should be placed on lowering saturated fats consumption and minimizing or eliminating trans fats.