Post by Gaz on Oct 12, 2017 12:19:55 GMT 10
Why do we need to eat fat?
Fat! Don’t be scared of it… You actually need it in your diet. Fat doesn’t directly make you “fat” – excess calories make you “fat”. It’s about getting the right balance.
Fat has had bad press, to the extent that some foods are designed and marketed as ‘fat-free’. But it isn’t all bad. In fact, getting some fat from our diet is absolutely vital.
In this section, you will find out what fats are, why we need them, what they do for us and where we find them in our foods.
Why do we need fat?
Virtually all natural foods contain some fat. It is in foods because both plants and animals use fats as the most economical way to store energy. It is needed for their growth, development and function when there is a shortage of food supply (or a shortage of sunlight in the case of plants).
Certain specific dietary fats have other essential functions. We are much like other animals so we do actually need some fat from our diet to survive. And while in general, as with most things, too much fat is bad, a certain amount is perfectly compatible with good health.
What is fat for?
A source of energy – Our body uses the fat we eat, and fats we make from other nutrients in our bodies, to provide the energy for most of our life-functions
Energy store – The extra calories that we consume, but do not need to use immediately, are stored for future use in special fat cells (adipose tissue)
Essential fatty acids – Dietary fats that are essential for growth development and cell functions, but cannot be made by our body’s processes
Proper functioning of nerves and brain- fats are part of myelin- a fatty material which wraps around our nerve cells so that they can send electrical messages. Our brains contain large amounts of essential fats
Maintaining healthy skin and other tissues. All our body cells need to contain some fats as essential parts of cell membranes, controlling what goes in and out of our cells
Transporting fat-soluble vitamins A, D, E and K through the bloodstream to where they are needed
Forming steroid hormones needed to regulate many bodily processes
Where do we find fats in our foods?
The fats that we eat in our foods are mostly “triglycerides”. These are made up of 3 (hence “tri”) fatty acids attached to a glycerol molecule.
Saturated fats are found mostly in animal products such as meat, cheese, milk, butter, cream and eggs.
Did you know? Animals being warm-blooded incorporate some saturated fats into tissues to keep them more solid. Cold-blooded fish, and plants, however cannot include much saturated fat because they would become too stiff. However some oils from tropical plants such as palm oil and coconut oil do contain some saturated fats.
The main unsaturated fats are monounsaturated, found particularly in foods such as olive oil, rapeseed oil, peanuts and avocados.
Polyunsaturated fats are mostly found in plant foods such as nuts, seeds and vegetable oils, and in cold-blooded sea-foods. In natural foods, they come protected with antioxidant vitamins. There are two main classes polyunsaturated fatty acids, omega-3 and omega-6. These include the essential fatty acids. Oily fish (e.g. herring, salmon and mackerel) is a good source of omega-3, while omega-6 is mainly found in plant foods such as sunflower oil and rapeseed oil.
Trans fats can be natural or artificial. They are mostly artificially created through a process known as hydrogenation (which involves heating and chemical structure change). Artificial trans fats are mostly found in fast foods, fried foods and commercial baked products such as cookies and are the most unhealthy fats (even worse than saturated fats!). Natural trans fats can be found in small amounts in milk and beef, and in quite large concentration in cheese.
Why do we need cholesterol?
Now, we understand that we do actually need some fat in our diet for survival and in the end, it is all about getting the amount and the right balance!
What are trans fats?
There are two broad types of trans fats found in foods: naturally-occurring and artificial trans fats. Naturally-occurring trans fats are produced in the gut of some animals and foods made from these animals (e.g., milk and meat products) may contain small quantities of these fats. Artificial trans fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid.
The primary dietary source for trans fats in processed food is “partially hydrogenated oils." Look for them on the ingredient list on food packages. In November 2013, the U.S. Food and Drug Administration (FDA) made a preliminary determination that partially hydrogenated oils are no longer Generally Recognized as Safe (GRAS) in human food.
Why do some companies use trans fats?
Trans fats are easy to use, inexpensive to produce and last a long time. Trans fats give foods a desirable taste and texture. Many restaurants and fast-food outlets use trans fats to deep-fry foods because oils with trans fats can be used many times in commercial fryers. Several countries (e.g., Denmark, Switzerland, and Canada) and jurisdictions (California, New York City, Baltimore, and Montgomery County, MD) have reduced or restricted the use of trans fats in food service establishments.
How do trans fats affect my health?
Trans fats raise your bad (LDL) cholesterol levels and lower your good (HDL) cholesterol levels. Eating trans fats increases your risk of developing heart disease and stroke. It’s also associated with a higher risk of developing type 2 diabetes.
Why did trans fats become so popular if they have such bad health effects?
Before 1990, very little was known about how trans fat can harm your health. In the 1990s, research began identifying the adverse health effects of trans fats. Based on these findings, FDA instituted labeling regulations for trans fat and consumption has decreased in the US in recent decades, however some individuals may consume high levels of trans fats based on their food choices.
Which foods contain trans fats?
Trans fats can be found in many foods – including fried foods like doughnuts, and baked goods including cakes, pie crusts, biscuits, frozen pizza, cookies, crackers, and stick margarines and other spreads. You can determine the amount of trans fats in a particular packaged food by looking at the Nutrition Facts panel. However, products can be listed as “0 grams of trans fats” if they contain 0 grams to less than 0.5 grams of trans fat per serving. You can also spot trans fats by reading ingredient lists and looking for the ingredients referred to as “partially hydrogenated oils.”
Are there naturally occurring trans fats?
Small amounts of trans fats occur naturally in some meat and dairy products, including beef, lamb and butterfat. There have not been sufficient studies to determine whether these naturally occurring trans fats have the same bad effects on cholesterol levels as trans fats that have been industrially manufactured.
How much trans fat can I eat a day?
The American Heart Association recommends cutting back on foods containing partially hydrogenated vegetable oils to reduce trans fat in your diet and preparing lean meats and poultry without added saturated and trans fat.
How can I limit my daily of trans fats?
Read the Nutrition Facts panel on foods you buy at the store and, when eating out, ask what kind of oil foods are cooked in. Replace the trans fats in your diet with monounsaturated or polyunsaturated fats.
Regulating Your Intake of Saturated and Trans Fats
The American Heart Association recommends that adults who would benefit from lowering LDL cholesterol reduce their intake of trans fat and limit their consumption of saturated fat to 5 to 6% of total calories.
Here are some ways to achieve that:
Eat a dietary pattern that emphasizes fruits, vegetables, whole grains, low-fat dairy products, poultry, fish and nuts. Also limit red meat and sugary foods and beverages.
Use naturally occurring, unhydrogenated vegetable oils such as canola, safflower, sunflower or olive oil most often.
Look for processed foods made with unhydrogenated oil rather than partially hydrogenated or hydrogenated vegetable oils or saturated fat.
Use soft margarine as a substitute for butter, and choose soft margarines (liquid or tub varieties) over harder stick forms. Look for “0 g trans fat” on the Nutrition Facts label and no hydrogenated oils in the ingredients list.
Doughnuts, cookies, crackers, muffins, pies and cakes are examples of foods that may contain trans fat. Limit how frequently you eat them.
Limit commercially fried foods and baked goods made with shortening or partially hydrogenated vegetable oils. Not only are these foods very high in fat, but that fat is also likely to be trans fat.
Read the full American Heart Association Diet and Lifestyle Recommendations.