Dietary Fats and Oils

There are two kinds of dietary fats- visible and invisible fat.

1. Visible fats include oils, butter, animal fat, etc.

2. Invisible fat cannot be seen with the naked eye but is present in small quantities in foods such as wheat, rice, and pulses.

Typically, the fats and oils we use consist primarily of either saturated or unsaturated fatty acid chains.

• Saturated fats lack double bonds in their chemical structure, solidifying at room temperature. They are primarily sourced from animal origins, although some are obtained from plants. Examples include butter, lard, palm kernel oil, and coconut oil.

• Unsaturated fats feature one or more double bonds in their chains, remaining in liquid form at room temperature. They are generally derived from plant sources, such as soybean oil and safflower oil. Fish oil, on the other hand, comprises a higher proportion of unsaturated fats compared to saturated fats.

Importance of Fats and Oils in Human Nutrition

• Fats and oils play a crucial role in supporting basic metabolic functions in the human body. They are essential sources of essential fatty acids (EFAs). These EFAs, namely linoleic acid (omega-6) and α-linolenic acid (ALA) (omega-3), are vital nutrients that the body cannot produce on its own and must be obtained from the diet. Maintaining a proper balance, with a ratio of 5:1 to 10:1 between linoleic acid and α-linolenic acid, is essential.

• α-Linolenic acid gives rise to important derivatives such as ecosa-pentaenoic acid (EPA) and docosa-hexaenoic acid (DHA). Adequate intake of EFAs, comprising 1-3% of total calories, is necessary to prevent deficiencies that can lead to conditions like impaired brain growth, mental retardation, learning difficulties, dermatitis, hair loss, and poor wound healing.

• Fats and oils are also necessary for the absorption of fat-soluble vitamins, including vitamin A, D, E, and K. Without sufficient dietary fats, the body may struggle to absorb these vitamins, potentially causing various metabolic disorders such as night blindness, osteoporosis, bleeding from the skin and mucosa, dry skin (phrenoderma), and increased susceptibility to infections.

• Additionally, vegetable oils serve as valuable sources of plant sterols, notably ß-sitosterol and campesterol. The FDA has approved the claim that foods containing at least 0.4 grams per serving of plant sterols, consumed twice daily with meals to achieve a daily intake of at least 0.8 grams, as part of a low saturated fat and cholesterol diet, may reduce the risk of heart disease. These phytosterols competitively inhibit cholesterol absorption in the gut, resulting in cholesterol levels reduction by 10% to 15%.

• Fats are also calorie-dense, providing 900 calories per 100 grams of cooking oil. They serve as an important energy reserve, readily available during times of starvation, illness, and cold weather.

• Moreover, fats and oils high in mono-unsaturated fats, such as those found in olive oil, canola oil, peanut oil, and sesame oil, can help lower LDL-cholesterol levels in the bloodstream.

Constraints of Dietary Fats and Oils

Except for the essential need for fat-soluble vitamins and essential fatty acids, there is no specific necessity for dietary fats and oils, as long as the diet supplies sufficient nutrients for energy.

Excess carbohydrates, in the form of glucose, eventually transform into fatty acids due to the influence of the insulin hormone. Individuals who consume omega-6 and omega-3 fats in a ratio exceeding 10:1 should counterbalance this by incorporating omega-3-rich foods such as fish, leafy greens, and algae into their diets.

Excessive fat intake in the diet results in the circulation of components such as triglycerides and cholesterol in the bloodstream. These components deposit in varying proportions within different organs and tissues in the body, potentially leading to conditions such as obesity, coronary artery disease, diabetes, peripheral vascular disease, stroke, and more.

Although the average American diet consists of 35-40% of calories from fat, most current recommendations advocate for limiting dietary fat to 30% or less of total calorie intake. Saturated fats should not exceed 5-10% of energy consumption, while monounsaturated and polyunsaturated fatty acids should each make up 10% of the total energy intake.

Below is the table with in-depth analysis of some of commonly used dietary fats and oils:-

SFA= Saturated fatty acids

MUFA= Mono-unsaturated fatty acids

PUFA= Poly-unsaturated fatty acids

ω-3= Omega 3 fatty acids

ω-6= Omega 6 fatty acids

Also read ≻≻-

≻≻-High cholesterol and Health.

≻≻-Essential fatty acids.

≻≻-Trans fats.

≻≻-Back to Home page from fats and oils.

Further reading and References:

US-FDA-Trans fats

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