Written by: Sarah Brown
As the last part of our nutritional series (see carbohydrates and protein), we’re going to dwell on dietary fat, a topic most people are aware of but have probably been misguided by mainstream ideas on certain points. Fact is, fat is healthy. Your body needs it for growth and repair just like any other nutrient. But the problem lies in the type, processing, and cooking which makes it either a friend or foe. So to make sure everything is geared towards healthy weight loss, here’s what you need to know.
What is fat?
Fat is another macronutrient that is also known as triglyceride (TGA). This molecule is composed of four constituents: 3 fatty acids and 1 glycerol.
The focus of this article will be on fatty acids since are often cited in nutritional regimens, plus are basic to every intelligent dieter. For simplicity’s sake I’ll use fat and fatty acids interchangeably from this point onward to avoid confusion.
Going back to the topic, fats are divided into two classes: saturated and unsaturated. The unsaturated ones are further classified into monounsaturated and polyunsaturated.
Monounsaturated fats – the good old olive oil found in Mediterranean diets. One reason it’s often cited in a multitude of studies is because of its wonderful effects on lowering bad cholesterol and raise good cholesterol. Other common sources are found in avocado, peanuts, groundnuts, and tree nuts.
Polyunsaturated fats (PUFA) – the ones people think are healthy but handle erroneously (you’ll know why in a few paragraphs). Recently, they’ve been linked to inflammation due to high consumption. But nevertheless PUFA are essential for bodily functions. Sources include any seed oil such as canola, sunflower or safflower oil.
Yikes! The bad ones…
They’re mainly found in butter, meat, or any animal and tropical fat (i.e. coconut oil and palm oil). Unfortunately saturated fats have been excessively demonized over the years (there’s a 99% chance someone told you to avoid these), but today, you’ll get to see the bigger picture of what’s really going on.
Before I discuss the difference between good and bad fat, let us answer the most important question:
Why is fat important?
You’ve probably heard to go easy on fat since they give love handles quite quickly (something everyone agrees upon). Despite their importance in cuisine for turning food palatable and tasty, the high calorie content (9 calories for every gram) makes them easy to overeat. But aside from it, fats are still an essential component of a well-balanced diet. Below are a few reasons why:
- Just like protein, fats are used in cell signaling to provide efficient metabolic processes
- Vitamins like A,D,E, and K are fat soluble, which means fats are needed in order to digest these vitamins
- Fat helps in maintaining healthy skin and hair by secreting sebum (basically a fat) that lubricates the skin and makes it waterproof
- Fat is also useful in insulating organs against shock and maintaining body temperature
- Fat is as well used to buffer against different diseases
- In fact, your brain is even made up of 60% fat!
The Bad Guy: What makes fat unhealthy?
Unhealthy fats are those that underwent industrial processing to become nonperishable, like:
- Hydrogenated fat such as margarine
- Trans-fatty acids found in fast foods
- Most cooking oils (e.g. safflower, soybean oil) due to their weak resistance to oxidation (a process that turns good oils into bad ones)
The distinguishing feature of bad fats is the word “processed”. Usually, these are man-made. For example, vegetable oil seen in supermarkets have been hydrogenated (a procedure that injects oil with hydrogen) in order to prolong shelf life. Thus, polyunsaturated fats are not bad “per se” provided they’re not humanly altered, but once they’re processed (i.e. hydrogenated), they turn into bad guys. This eventually leads to health problems like inflammation.
What about trans-fatty acids?
That’s another term for hydrogenated fat. You see, when oil is hydrogenated it becomes unhealthy due to the hydrogen turning normal fatty acids into trans-fatty acids (a bad guy). And the problem is most fast food use vegetable oil for cooking (polyunsaturated fat is easily oxidized by heat, leading to an increase in trans-fat content).
So what’s the best cooking oil?
Among the 3, saturated fat like butter and coconut oil has shown to possess the highest resistance to oxidation. Followed by olive oil that can be used for a little bit of stir-fry (but not for deep frying). At this point you might be wondering “Experts say saturated fat is unhealthy, then why use it for cooking?”
At present, the theory that saturated fat causes disease is starting to take a turn. Objective, meticulous scientists are making rounds in previous literature proving the inaccuracy of most research, demonstrating how saturated fat is not the culprit, but refined sugar. Because of the discrepancy you’ll always find two separate schools of thoughts: one proclaiming to eat all the fat you want and the other claiming fat is a sin. So which is right?
As the old adage goes anything in excess is bad will keep you safe from both extremes. Science is evolving, and at present there’s still enough turmoil to completely trust one or the other. But for practical purposes, always keep everything in balance. You’ll most likely get the best of both worlds. After all, you’re not going to eat everything with saturated fat, are you? A drizzle of olive oil, a few servings of nuts, fish and avocado will give what your body needs. Bottom line is: stick to variety of whole foods. You’ll never go wrong.
The Good Guy: What makes fat healthy?
On the flip side a good type of fat doesn’t induce inflammation. Popularly, monounsaturated fats stand out in this category; especially fatty acids coming from olive oil, avocado or seed oil have beneficial effect. Unfortunately as mentioned earlier, the rise in excess PUFA over the last decades has shown to increase inflammation (one reason why vegetable oil shouldn’t be used for cooking). Therefore it always boils down to one simple rule: in order to stay healthy, cook with saturated fat and drizzle with the rest of other oils.
Just like protein, fat also has essential components (the body cannot make its own supply), namely, omega 3 and omega 6 polyunsaturated fats found in poultry, eggs, nuts, vegetable oil and oily fishes such as salmon and mackerel. There’s no need to squeeze your brain for it. Stick to a balanced diet and you’ll get them anyway.
As mentioned above, complete avoidance of one type or the other isn’t good either. So keep a well-balanced ratio to stay healthy! Fats aren’t all bad after all; as long as you choose the right one, for the right purpose.
Key points to take home:
- Fat just like protein and carbs is another macronutrient also called Triglyceride (TGA).
- There are 3 main types of fat: saturated, monounsaturated, and polyunsaturated.
- Common sources of monounsaturated fats are avocado, olive oil, peanuts, groundnuts, and tree nuts.
- Polyunsaturated fat are found in seed oil such as canola, sunflower or safflower oil, and vegetable oil.
- Saturated fats are found in meat and coconut or palm oil.
- Bad fat increases inflammation. This includes hydrogenated oils found in fast foods and vegetable oil used for cooking.
- Good fat is found in monounsaturated fats like avocado and olive oil.
- Essential fatty acids (the ones your body cannot make) are omega 3 and omega 6 (PUFA) found in fishes and vegetable oil.
- Don’t eat anything in excess. Get an equivalent amount of fat from the 3 types to get a healthy dose.