Dietary fats and oils yield 9 calories/g, whereas, carbs and proteins produce only 4 calories/gm. Foodies know that nuts and oil seeds are very good sources of fat. They are rich in energy, dietary fats, sources for essential fatty acids and vitamin E. Furthemore, they transport fat-soluble vitamins/hormones.
There are basically two types of dietary fats. Visible fats include butter, oils and animal fat etc. Invisible fats are in foods like rice and wheat. Most of the fats and oils we use are either saturated OR un-saturated fatty acid chains.
Unsaturated fats have one or more double bonds and are liquid at room temperatures. In general, they are derived from plants. Examples are: soybean oil, safflower oil, etc. Fish oil, on the other hand, is composed mainly unsaturated fats—with little saturated fats.
Saturated fats contain no chemical double bonds. They are solid at room temperatures and commonly derived from animals and some from plant sources. Examples: butter, lard, palm kernel oil, coconut oil, etc.
Why We Need Fats And Oils
They provide essential fatty acids (EFA) or nutrients required by the body. EFAs are linoleic acid and α-linolenic acid.α-Linolenic acid (ALA) is known as omega-3 and linoleic acid is called as omega-6 essential fatty acids.
Deficiencies of EFAs results in impaired brain growth, mental retardation, learning difficulties, dermatitis (dryness of skin), hair loss and poor wound healing.
The four fat-soluble vitamins namely vitamin A, D, E and K are required fats and oils for food to be absorbed through our gut. Inadequate fats may result in night blindness, osteoporosis, bleeding from skin and mucus membranes, dry skin (phrenoderma) and susceptibility to infections.
Vegetable oils are a good source Of plant sterols. The FDA states: "Foods containing at least 0.4 gram per serving of plant sterols, eaten twice a day with meals for a daily total intake of at least 0.8 gram, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease." Phyto-inhibits cholesterol absorption across the gut and thereby can reduce cholesterol levels by 10% to 15%.
Fats are also high in calories. An average 100 g of cooking oil provides 900 calories. Fats function like reserve energy that is available during the times of starvation, illnesses and cold-weather conditions.
Fats and oils high in mono-unsaturated fats as in olive, canola, peanut, sesame…etc., help lower LDL-cholesterol in the blood.
Fats & Oils: Limitations
Excessive fats in the diet circulate astriglycerides and cholesterol in the blood. These deposit in different organs and tissues inside our body leading to obesity, coronary artery disease, diabetes, peripheral vascular disease, strokes, etc.
The average American diet contains 35-40% of calories as fat. The current recommendations are to limit dietary fat to 30% or less of total calories. Not more than from 5-10% of energy should come from saturated fats. 10% should be from mono-unsaturated and another 10% from poly-unsaturated fats!
Lisa DeFazio’s a leading nutrition expert and a Master’s degree level Registered Dietitian, so be sure to check out her website and follow her on Twitter for more tips and videos — and if U wanna know more about Fats & Oils OR anything else, U can always email us at Questions@FitPerez.com!!