If you're under 35 years old, you probably don't remember the low-fat craze that inundated America from the late sixties to the turn of this century. It led food companies to remove fats from whole foods and replace them with empty carbs, sugars, and other filler ingredients.
Mathematically it made sense, fat has more than twice the calories (9) of protein or carbs (4). Unfortunately, there were many unintended consequences, such as highly processed foods and a continued growth in Americans' waistlines.
Nutrition science evolved, and a more nuanced understanding of the different types of fats emerged. As a result, we are now encouraged to consume healthy fats as part of a balanced diet.
Let's dive into a bit more detail.
Body fat is an energy store
Fats can either be consumed from food or manufactured by the body. In either case, fat is an energy time machine. Instead of carbs that are used for immediate use by muscles and the brain, fat is like a battery storing energy for use tomorrow, the day after, or even longer. This served our hunter-gatherer forefathers quite well.
During hunting season and periods of plenty, early humans ate abundantly and gained weight in the form of fat. When food was scarce, their bodies burned the fat as a source of highly concentrated energy.
Thankfully today, most people do not suffer from prolonged shortage of food.
Dietary fats make food tasty and keep us satiated
We'll start with the obvious. Fatty food tastes good. A bit of fat added to a meal can help you stay satiated for longer than a meal without any fat.
Saturated fat, which is a dietary fat to limit, can be found in
• Red meats such as beef and pork
• Chicken skin
• Whole-fat dairy - milk, butter, yogurt, and cheese
• Ice cream
• Some oils such as coconut and palm oil
Unsaturated fats are recommended as part of a healthy diet. They are divided into 2 groups:
Monounsaturated fats, which can be found in
• Avocados
• Olives and olive oil
• Canola, peanut, and sesame oils
• All sort of nuts - for example almonds, pecans, cashews
• Peanuts and peanut butter
Polyunsaturated fats can be found in
• Sunflower, sesame, and pumpkin seeds
• Flaxseed
• Walnuts
• Fatty fish (salmon, tuna, mackerel, herring, trout, sardines) and fish oil
• Soybean products - tofu, soy milk, and soy oil
There are also industrial trans-fats, extremely unhealthy, but they are hardly found in food product any more.
Some dietary fats are "Essential"
Dietary fat is constructed from building blocks known as fatty acids. Although the body can manufacture its own fat, there are two types of fatty acids that must be sourced from food:
• linoleic acid (omega-6)
• alpha linolenic acid (omega-3)
These fatty acids are required for creation of cell membranes, especially in nerve tissue. They are also converted into compounds that help regulate biochemical processes inside cells.
Omega 3 fats
Omega-3 is actually a family of fatty acids which includes alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). All three are polyunsaturated (reminder: that means good).
Omega-3 has been shown to help with multiple benefits including raising the IQ of unborn babies, better heart health, and brain function.
Not all omega-3 fatty acids yield the same benefit. They are further classified into 2 groups - "long chain" such as DHA and EPA, and "short chain" such as ALA (alpha linolenic acid). The long chain fatty acids are the ones that are considered most beneficial. They are readily available from oils of cold water fish such as salmon, sardines, and mackerel. The short chain ALA is found in flax seeds and chia seeds for example.
Fats aid in absorption of some micronutrients
Some essential micronutrients – Vitamin A, D, E, and K – cannot be absorbed by the body without the presence of fat. That's why adding a bit of olive oil to your salad is actually a good idea!
Fat protects vital organs
Another important function of fats is to provide some cushioning and protection for important organs in the body. Obviously too much fat is unhealthy, but so is too little.
Bottom Line
Whatever you do, don't replace fats with unhealthy carbs.
Going on a weight loss diet does not mean completely avoiding fats. What fats do you regularly incorporate in your meals?
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