Fat

Fat: What is it and how much do we need?

Fat is one of the main types of nutrients that provide energy and structure to living things. It is found in many foods, especially animal products and some plant oils. Fat can be classified into different types based on its chemical structure and health effects. Some fats are essential for human health, while others can increase the risk of heart disease and other chronic conditions.

Types of fat

Fat is composed of molecules called triglycerides, which consist of three fatty acids attached to a glycerol backbone. Fatty acids can vary in length, shape, and degree of saturation. Saturation refers to the number of hydrogen atoms attached to the carbon atoms in the fatty acid chain. The more hydrogen atoms, the more saturated the fatty acid is.

• Saturated fats are fats that have only single bonds between the carbon atoms in the fatty acid chain. They are solid or semisolid at room temperature and are mostly found in animal foods, such as meat, butter, cheese, cream, and lard. Some plant foods, such as palm oil and coconut oil, also contain high amounts of saturated fats. Saturated fats can raise the level of low-density lipoprotein (LDL) cholesterol in the blood, which can increase the risk of heart disease and stroke.

• Unsaturated fats are fats that have one or more double bonds between the carbon atoms in the fatty acid chain. They are liquid at room temperature and are mostly found in plant foods, such as vegetable oils, nuts, seeds, and avocados. Some animal foods, such as fish and eggs, also contain unsaturated fats. Unsaturated fats can lower the level of LDL cholesterol in the blood and increase the level of high-density lipoprotein (HDL) cholesterol, which can protect against heart disease and stroke. Unsaturated fats can be further divided into two categories: monounsaturated fats and polyunsaturated fats.

• Monounsaturated fats are fats that have one double bond between the carbon atoms in the fatty acid chain. They are found in foods such as olive oil, canola oil, peanut oil, almonds, cashews, and peanuts. Monounsaturated fats can help improve blood cholesterol levels and regulate blood sugar levels.

• Polyunsaturated fats are fats that have two or more double bonds between the carbon atoms in the fatty acid chain. They are found in foods such as soybean oil, corn oil, sunflower oil, walnuts, flaxseeds, and fish. Polyunsaturated fats can help lower blood pressure and inflammation and prevent blood clots. Polyunsaturated fats include two types of essential fatty acids that the body cannot make itself: omega-3 fatty acids and omega-6 fatty acids.

• Omega-3 fatty acids are polyunsaturated fats that have three double bonds between the carbon atoms in the fatty acid chain. They are found in foods such as salmon, mackerel, herring, sardines, anchovies, chia seeds, hemp seeds, and walnuts. Omega-3 fatty acids can help reduce inflammation, improve brain function, and lower the risk of heart disease, stroke, depression, dementia, and some cancers.

• Omega-6 fatty acids are polyunsaturated fats that have six double bonds between the carbon atoms in the fatty acid chain. They are found in foods such as soybean oil, corn oil, sunflower oil, safflower oil, sesame oil, pumpkin seeds, and sunflower seeds. Omega-6 fatty acids can help regulate blood pressure and blood clotting and support skin health and wound healing.

Why do we need fat?

Fat is an essential part of a healthy diet because it provides energy and structure to living organisms. Fat has several functions in the body:

• Fat is a source of energy for cells and tissues. Each gram of fat provides about 9 calories (37 kJ) of energy when burned or metabolized by the body.
• Fat is a storage form of energy for future use. Excess calories from food are converted into fat and stored in adipose tissue under the skin and around organs.
• Fat is a carrier of fat-soluble vitamins (A,D,E,K) that are needed for various biological processes. Fat helps absorb these vitamins from food and transport them to where they are needed in the body.
• Fat is a component of cell membranes that regulate what enters and exits cells. Fat also helps maintain fluid balance and cell signaling within and between cells.
• Fat is a precursor of hormones that regulate growth, development, metabolism, reproduction, mood, and stress response.
• Fat is a cushion for organs and joints that protects them from shock and injury.
• Fat is an insulator for body heat that helps maintain body temperature.

How much fat do we need?

The amount of fat that we need depends on various factors such as age, activity level , health status ,and personal preference . According to the Dietary Guidelines for Americans 2020-2025 , fat should provide 20% to 35% of total daily calories for adults . This means that for a person who consumes 2 ,000 calories per day , about 400 to 700 calories should come from fat .

However , not all fats are created equal . Some fats are more nutritious and beneficial than others . In general , it is recommended to choose unsaturated fats over saturated fats and trans fats ,and to balance omega-3 fatty acids with omega-6 fatty acids . Unsaturated fats include vegetable oils , nuts , seeds , avocados ,and fish ; while saturated fats include animal foods , palm oil ,and coconut oil . Trans fats are artificially produced fats that have been chemically altered to make them more solid or stable . They are found in processed foods such as margarine , shortening , baked goods , fried foods ,and snacks . Trans fats can raise LDL cholesterol levels , lower HDL cholesterol levels ,and increase the risk of heart disease , stroke ,and type 2 diabetes .

Therefore , it is advisable to limit the intake of saturated fats to less than 10% of total daily calories ,as suggested by the Dietary Guidelines for Americans 2020-2025 . This means that for a person who consumes 2 ,000 calories per day , no more than 200 calories should come from saturated fats . It is also advisable to avoid trans fats as much as possible by reading food labels carefully and choosing products that do not contain partially hydrogenated oils .

Conclusion

Fat is a vital nutrient that provides energy and structure to living things . It can be classified into different types based on its chemical structure and health effects . Some fats are essential for human health , while others can increase the risk of heart disease and other chronic conditions . Fat should provide 20% to 35% of total daily calories for adults , but it is important to choose unsaturated fats over saturated fats and trans fats for optimal health benefits .