Saturated Fats

The words oils, fats, and lipids are all terms used to refer to foods that should be considered fats. Fatty compounds can be chemically saturated or unsaturated. All fats consist of fatty acids (chains of carbon and hydrogen atoms, with an oxygen atom at one end and occasionally other molecules) bonded to a backbone structure, often glycerol (a “backbone” of carbon, hydrogen, and oxygen).

Fats as a class of food are the source for essential fatty acids (nutrients that our body needs but cannot produce and are taken in by eating). Fats bind to lipid soluble vitamins (A, D, E, and K), making them accessible for our bodies’ needs through fat cells that store and release energy. Fat is the most concentrated source of energy in foods, and when kept at reasonable levels in our diet, are not unhealthy. Fats become unhealthy for us when they are excessively eaten, leading to an increase in lipid levels in our body and the consequent deposition of these lipids in our vasculature.

Saturated fats and trans fats are considered the unhealthy fats. Saturated fats are fully hydrogenated, meaning that there is a hydrogen on every carbon and the molecule is very stable (are usually solid at room temperature) and hard to break up. This allows them to store and ultimately provide more energy than carbohydrates or proteins—9kcal for every gram of fat—and makes them more likely to stick to the body as cholesterol.

Foods that contain a high proportion of saturated fat are butter, tallow, lard, coconut oil, cottonseed oil and palm kernel oil; dairy products (especially cream and cheese); meat; as well as foods meant to be stored for long periods of time. Many Third World countries depend on these staples as daily meals.

Trans fats are a type of unsaturated fats, where double bonds between carbons in the backbone “kink” the chain. They are usually made from saturated fats. The kinking of the fat molecule makes it easier for them to stick together, leading to cardiovascular problems when eaten in excess. Trans fats allow the foods containing them to last longer, so are used in products that have longer shelf lives (i.e., fast foods, snack foods). They are also found in meat.

Excess consumed fats are an important cause of dyslipidemia and cardiovascular disease such as atherosclerosis. There is clear evidence from randomized controlled trials that significant improvements in blood lipid parameters can be achieved by modifying dietary fat intake, and for some time, there has been a consensus that reduced consumption of saturated fat should be a goal for the populations of many high-er-income countries. For lower-income countries, the goal should be to limit the amount of fats in the diet—whether indigenous or other—to no more than 30 percent of daily calories.