Understanding Fat
When it comes to the human body, fat doesn’t have to be a dirty word. Although most of us want to have less of it, we still need some fat to function (along with protein and carbohydrates).
If you’re interested in losing weight and living a healthy, balanced lifestyle, understanding fat better can be invaluable. In this article, we explore the building blocks of fat – glycerol and fatty acids – before explaining why you need fatty acids in your diet and where you can find the healthiest ones.
So, let’s start with a little bit of chemistry.
Glycerol and Fatty Acids: The Science of Fat
Fats (also known as lipids) are solid at room temperature and consist of two main parts: glycerol and fatty acids, each made up of a number of carbons, hydrogens, and oxygens.
- Glycerol is an alcohol with three carbons, five hydrogens, and three hydroxyl groups (a group composed of one oxygen atom bonded to one hydrogen atom).
- Fatty acids, meanwhile, have a long hydrocarbon chain with a carboxyl group attached (a group made up of a carbon atom that’s double-bonded to an oxygen atom and singly bonded to a hydroxyl group).
At a molecular level, the fatty acids are attached to each of the glycerol backbone’s three carbons. Since fat is essentially three fatty acid chains and a glycerol, they’re sometimes referred to as triacylglycerols or triglycerides.
What Are Triglycerides?
Triglycerides are a type of fat found in your blood.
Your body converts any calories you consume but doesn’t need to use right away into triglycerides, which are stored in your fat cells to be used as energy later. When your body doesn’t have enough glucose (sugar) for energy, it burns your fat stores instead.
Alongside the far more common triglycerides, you also get diglycerides (two fatty acid chains and glycerol) and monoglycerides (one fatty acid chain and glycerol). You’ll rarely consume mono- and diglycerides, but they do pop up naturally in some oils and processed foods.
However, most of the fat you eat, including animal fats and plant-based oils, is made up of triglycerides. Enzymes called lipase break down triglycerides into monoglycerides and diglycerides during digestion, and when they enter your bloodstream, they’re turned back into triglycerides.
As we’ll discover, there are a few different fatty acids in triglycerides. According to the British Nutrition Foundation, “The presence of specific fatty acids at different positions on the glycerol molecule will also influence its characteristics (i.e. melting point and digestibility).”
What Are the Different Types of Fatty Acids?
So, glycerol and fatty acids are the building blocks of fat. Check.
This applies to both the fat in your body and the fat in the food you eat. And when you consume something containing fat, your body breaks it down into fatty acids.
The following are the three types of fatty acid. Each one affects our health in various ways:
- Saturated: This fatty acid gets its name because the carbon chains of saturated fats have no room for hydrogen atoms (hence they are “saturated”). They raise low-density lipoprotein or LDL cholesterol levels (otherwise known as the “bad” cholesterol) which, in turn, increases the risk of high blood pressure and heart disease.
Read More: What Are Normal Cholesterol Levels? - Monounsaturated: If some of the hydrogen atoms are missing, replaced by a double bond between the carbon atoms, then the fatty acid is “unsaturated.” And when it has one double bond, it’s said to be “monounsaturated” (mono = one). Eating unsaturated fats instead of their saturated counterparts can help lower your cholesterol.
- Polyunsaturated fatty acids: If there’s more than one double bond present, the fatty acid is said to be “polyunsaturated” (poly = many). Polyunsaturated fats can also help lower your cholesterol levels.
Here endeth our chem lesson. Phew! So, why does this matter? Why do you need healthy fatty acids in your diet? Let’s find out.
Why Do You Need Fatty Acids?
All fats contain fatty acids, but in the interests of health and wellbeing, you’ll want to focus on the monounsaturated and polyunsaturated varieties. Essential fatty acids, including omega-3 and omega-6, are especially important as your body can’t produce them naturally. You need to get your fair share from your diet.
The trouble is, most foods contain a mixture of the different types of fatty acids we discussed above. Even foods high in mono- or polyunsaturated fats can still contain unhealthy saturated fat, too.
That said, if you’re careful about what you’re eating, focusing on foods with a high ratio of healthy fats to unhealthy fats, you should experience the benefits of unsaturated fatty acids — while avoiding the adverse effects of too much saturated fat.
These benefits include:
- Heart health: Eating healthy fats can help lower your cholesterol levels and reduce your risk of heart attack, heart disease, and stroke.
- Skin health: Omega-3 (linolenic acid) and omega-6 (linoleic acid) are both vital for healthy skin. They help retain moisture and keep irritants at bay. Dry, flaky, unhealthy-looking skin is just one sign of omega-3 deficiency.
- Brain health: Omega-3 fatty acids are also crucial for brain health. It’s one of a number of vitamins for memory and concentration, with studies suggesting that older people who get higher amounts in their diet demonstrate a better memory.
You can add more healthy fatty acids to your diet by eating more of the following:
- Fatty fish: Rich in omega-3 fatty acids, eating fish like salmon, herring, and sardines twice a week should deliver more than your fair share.
- EVOO: Extra virgin olive oil is high in monounsaturated fatty acids, making it a vital part of a heart-healthy diet.
- Flaxseed oil: Alpha-linolenic acid (ALA) is another essential fatty acid, and you’ll find it in abundance in flaxseed oil.
- Walnuts: Not keen on fish or flaxseed oil? Well, a one-ounce serving of walnuts (around seven nuts) contains 2.5g of ALA, along with omega-3 and omega-6 fatty acids. Just go easy on them — walnuts are high in calories!
Key Takeaways
Understanding that not all fat is created equal is crucial to living a healthy, balanced lifestyle. Scanning ingredients and choosing foods rich in mono- and polyunsaturated fats (and cutting down on saturated fats) can help improve your heart, brain, and skin health.
Get inspired: Check out our Daily Health articles for more diet and lifestyle tips & advice.
FAQs
What do Glycerol and Fatty Acids do?
Glycerol and Fatty Acids are the compounds which together make fat, or lipids. Together, Glycerol and Fatty Acids are known as triglycerides, diglycerides, or monoglycerides, depending on their form.
Is fat healthy or unhealthy?
Fat (or lipids) is essential to the healthy, normal functioning of the human body. Our body’s fat acts as a natural insulation layer, as well as reserve stores of sugar, for when your body is running low. However, some fats are healthier than others. Monounsaturated, or polyunsaturated fatty acids are ‘healthy’, whilst saturated fatty acids are ‘unhealthy’.
What does healthy fat do?
Healthy, unsaturated fatty acids promote good heart health, brain health, and skin health.
What foods contain healthy fats?
Fatty fish (like salmon, herring, and sardines), extra virgin olive oil, flaxseed oil, and walnuts contain healthy fats and fatty acids. Try to avoid processed food and foods high in saturated fats.
While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.
