Dietary fats are fats found in foods. They are an essential part of a healthy diet. It is generally recommended that consumption of dietary fats should not exceed 30 percent of a person's total daily caloric intake. Dietary fats that are liquid at room temperature are usually called oils. Dietary fats that are solid or partially solid at room temperature are called fats.

All dietary fats contain a mixture of saturated and unsaturated fatty acids. The type of fatty acid that predominates determines whether a fat is solid or liquid, and whether the dietary fat is characterized as saturated or unsaturated.

Fats such as tallow, lard and butter, and vegetable oils such as palm, palm kernel and coconut oils, which are harder at room temperature, contain higher levels of saturated fatty acids. They are considered saturated fats.

Oils such as soybean, canola, cottonseed, corn and other vegetable oils, which are liquid at room temperature, contain higher levels of unsaturated fatty acids. They are considered unsaturated fats. Unsaturated fats are further subdivided into monounsaturated and polyunsaturated fats.

Fatty acids are the building blocks of dietary fats. Fatty acids are classified as saturated or unsaturated depending on their chemical structure.

Trans fat acids are fatty acids in which the hydrogen atoms attached to the carbon-carbon double bond are located on opposite sides of the chain.

Trans fats are unsaturated fats that occur naturally in meats and dairy products and contain trans fatty acids. They are also formed when vegetable oils are processed into a solid or more stable liquid form.

Trans fats provide approximately 3 percent of total calories compared with 12 percent from saturated fat and 34 percent from total fat in the American diet. The majority of trans fats come from processed foods. Some trans fats in the diet come from animal sources such as meats and dairy products.

Trans fats are unsaturated, meaning they are not completely packed with hydrogen, but they are twisted in a way rarely seen in nature. Their unusual structure allows them to pack tightly together, which is why shortenings and margarine made with trans fats are solid at room temperature.

Research has shown that trans fats have effects similar to saturated fats on blood cholesterol. Saturated and trans fats have also similar physical properties, being hard at room temperature and providing texture to spreading products. However, from a public health point of view saturates could be more important because the diet contains more saturates then trans fats.

Products that are primarily used for cooking and baking purposes need to have a firmer texture to meet consumer needs. In such products, consistency is of prime importance to the consumer and therefore they have to have a higher level of saturated plus trans fats.

Hydrogenated oils containing trans fats have been used to improve the quality of foods by maintaining freshness and providing desirable texture.

Trans fat raises blood cholesterol and increases the risk of heart disease and other health conditions. Given the newly emerging consensus that trans fatty acids are not "neutral" but have adverse health effects, oil/fat manufacturers have been seeking to reduce the sum of saturates and trans in products, taking account of what customers think and want.

Within the fats, trans are the smallest part of diet providing approximately 3 percent of total calories. By contrast, saturated fats provide approximately 12 percent of total calories.

Trans fats elevate LDL (bad cholesterol) less than saturated fat, but they also decrease HDL cholesterol (good cholesterol) and increase inflammation, which is a risk factor for heart disease, stroke, diabetes and other chronic conditions. It is therefore generally recommended that people minimize the amount of trans fat they consume, while maintaining a healthy and balanced diet.
The American Heart Association advises consuming less than 300 milligrams of cholesterol each day and limiting total fat intake to no more than 30 percent of calories, saturated fat to no more than 7 percent of calories and trans fat to no more than 1 percent.

The USDA's Dietary Guidelines recommend consuming less than 300 milligrams of cholesterol each day, keeping total fat intake between 20 to 35 percent of calories, limiting calories from saturated fatty acids to 10 percent of daily caloric intake and keeping trans fatty acid consumption as low as possible.
The term is used to describe oil which has been lightly to moderately hydrogenated to shift the melting point to a higher temperature range and increase stability. Partially hydrogenated oils are used in a wide variety of food applications.

Partially hydrogenated oils are used in processed foods because they help produce food products that stay fresh longer and have a more desirable texture. It is not always desirable to substitute unhydrogenated oils because of differences in the way the oils work to produce acceptable food products.

The amount consumed of trans fats is very small, on average 5.8 grams, or 2.6 percent of total food energy. The proportion coming from margarines and spreads is decreasing as consumers switch to soft margarines and low fat spreads, which have very low trans fats levels.

Trans fat comes from a variety of food products. Approximately 60 percent comes from cereal products, meat and milk products including butter; about 30 percent comes from margarine and fat spreads; and the balance comes from a large number of minor sources.

Hydrogenated products: oils and fats, biscuits, confections, chips; natural (animal products): milk, butter, cheese, meat.

Trans fats are present in variable amounts in a wide range of foods, including most foods made with partially hydrogenated oils, such as baked goods and fried foods, and some margarine products. Trans fats also occur naturally in low amounts in meats and dairy products.

Yes, the edible oil industry has created a number of reduced and non-trans fat shortenings and oils using alternative processing techniques and/or by genetically altering the raw products like soybeans and canola.

Obesity is caused mainly by an imbalance in caloric intake and caloric consumption (usage) by the body.

The trans issue has been discussed in some detail as a result of popular interest in the effects of trans fats.

This is a continuous discussion. Individual views vary, but a consensus has emerged that trans fats have adverse health effects and therefore consumption should be limited, while maintaining a healthy and balanced diet.

In July 2003, the U.S. FDA issued a final rule requiring manufacturers of conventional foods and some dietary supplements to list trans fat on a separate line, immediately under saturated fat on nutrition labels. This policy became effective in 2006.