Dietary Fats: An overview

Fats, one of the most trendy words of the 21st century. In fact fats deserve their own paparazzi: they were just there minding their own business in our evolutionary life cycle until the 1970s and 1980s when fats became the villain. The scientific world, the government advisory groups and naturally the media all blamed fats as the culprit for the the number one killer in the United States: Heart Disease. With the devil fat gone we all cheered a future life free of heart attacks and strokes. Alas, this was nothing but a false dream. With the paparazzi deflated, they then turned fat into a hero, popularizing the Keto diet in the early 2000s. If low fat diet does not help, then a high fat diet must naturally help. That, as it turned out was a bust too.

So, lets get to know fats for who they really are:

What is fat:

Fat is made of up of carbon, hydrogen and oxygen molecules attached to each other in a chain called fatty acid. Various fatty acids then form complex three dimensional structures called fat. Naturally fats are found in nuts, seeds, avocado, dairy products, and vegetable oils. Animals in turn use these natural fats to synthesize their own fats.

Fat in humans:

We have learned to associate fat with bad body image. But fat is essential for body function:

• Fat is the building block of our cell walls. They form a layer around the cells that regulate the content of the cells. Without fats our cells fall apart. We cease to exist.

• Fatty acids are used to make various hormones essential in immune system and clotting factors.

• Fatty acids are essential building blocks of our nervous system and brain. They make us smart.

• Fats help us to absorb various vitamins such as Vitamin A, D, E and K.

And of course fats are essential in providing us with calories. We can only store a small amount of carbohydrates and many of our organs use fats as their main source of steady energy, For example the heart muscle depends more on fat than carbohydrates to generate the energy to pump blood.

Fun Fact: have you ever wondered why there is fat in meat, like the ones you buy at the store? Because fat is high in calories and muscles store it for use. This is why meat that comes from a more active body part (chicken thigh and wings) is higher in fat than meat from a less active body part (chicken breast).

Healthy fats to eat:

Fat is digested and absorbed in the small intestine and is circulated to the liver where we use dietary fats to generate our own fats. Since fat is insoluble in water (blood), we use transport proteins to move fat from one organ to another. These transport vehicles are complex structures made of proteins and fat, collectively referred to as lipoproteins. Lipoproteins are like buses that transport dietary fat from the small bowel to the liver and synthesized fats from the liver to their final destination.

However, sometimes these buses (lipoproteins) break down or are too large and get stuck on the road (blood vessels). This causes blockage of the road (blockage of the blood vessel). If the blockage is too large then the traffic stops. Blood flow is impeded: aka a stroke or heart attack.

What makes the buses too large or too damaged depends both on our genetics and our diet. Generically, some of us are lucky to have genes for more efficient buses, and some of us unfortunately are less fortunate and end up with a bad fleet despite our best efforts. But we can all control our diet. By eating healthy fats we improve the quality of our fleet. So, lets look at which dietary fats are healthy.

Omega 3s: super healthy. Lowers risk of heart disease and diabetes and is anti-inflammatory. Found in cold fresh water fish like Salmon, Tuna and Sardines. Vegetarian sources of Omega- are flax seeds, chia seeds and walnuts.

Poly and mono Unsaturated fats: super healthy. Also lower risk of heart disease and diabetes. Found in nuts, avocado, seeds and vegetable oils like Olive oil, avocado oil.

Saturated fat: used to be one of the bad guys, but we now know that saturated fats, in moderation, are not associated with heart disease. But at the same time, they are not as beneficial as Omega-3 and polyunsaturated fats. So, try to limit their use to foods that you truly love. Eat them for the food they are in, not for the benefits. Red meat and dairy products are rich in saturated fat.

Unhealthy Fat to Avoid:

Trans (hydrogenated) fat: This is the most harmful kind of fat and for the most part is banned in the United States. Hydrogenated fat does not occur naturally. Liquid vegetable oil is heated to high temperatures, hydrogen is added and then cooled. Hydrogenated fat is solid and much more stable, so it was used by the food industry to make food last longer and for solid products like margarine. Hydrogenated fat is directly associated with heart disease and has no place in our diet.

Seed Oils:

Seed oils, as the name suggests, are oils derived from plant seeds. These include flax seed oil, sunflower oil, canola oil, pumpkin oil and safflower oil. Seed oils are rich in polyunsaturated fats and are very healthy. Due to their high smoke point, they are a great choice for cooking. However, recently there has been a movement by the influencer crowd to discredit these oils as having inflammatory products. As of today, there is no studies to show that seed oils lead to inflammation or are associated with cardiovascular disease.

How to incorporate healthy fats in your diet:

Fats are one the of the three macronutrients, meaning our body needs them in a large quantity and depends on them for its daily energy use. But fats are also very rich in calories per serving size compared to carbohydrates and proteins. So they should take the least space in our plates. Fats are in most animal products and are the main source of cooking oil, so most of us get enough fat in our meals. What we should really focus on is the quality of the fat we include in our meals. Here are some tips on how to improve the quality of the fats you eat:

Cooking oils: Cooking oil gets absorbed in your food, so your choice matters. Avocado oil and seed oils have a high smoke point and are great options for cooking at high temperatures. Cooking olive oil is also very healthy but it has a lower smoke point, so avoid it for high temperature cooking.

Healthy oils in food:

• Breakfast:

  • eggs (the cholesterol in egg is not associated with heart disease).

  • Peanut or almond butter

  • flax seeds

  • avocado (use as spread on toast)

  • Greek yogurt or cottage cheese

  • Salmon

• Lunch/Dinner:

  • fish

  • white meat like chicken or pork

  • avocado (tip: use ripe avocado spread instead of mayo)

  • eggs

  • greek yogurt

  • red meat

  • nuts and seeds (main source for vegetarians)

• Snacks:

  • handful of nuts/seeds

  • avocado dip

  • Olives