The Truth About Fats in the Diet
bottom line up front
Over the decades, Fat in the diet has had a bad rep and it was recommended to avoid all dietary fat as it could potentially lead to unwanted health conditions. With newer research and a better understanding of the types of fat - we have learned that there are major differences: beneficial dietary fats (monounsaturated and polyunsaturated fats), not so beneficial (trans-fats) and controversial (saturated fats). Regardless - fat is necessary in our diet and is one of the three major macronutrients. It provides energy, satiation, and aids in bodily processes. There is no reason to avoid fat or even choose a “low-fat” option; instead focus on monounsaturated, omega-3 and omega-6 rich fats in balance, and choose (grass-fed, organic) versions of saturated fat when possible. Scroll below for a more in-depth explanation.
Functions of Fat
Fat (along with carbohydrates and protein) is essential in our diet and for proper bodily functions. Some of the functions are:
Provides energy. Fat is the most energy dense macronutrient - meaning it provides more calories per gram than carbohydrate and protein, more calories = more energy.
Absorb fat soluble vitamins (A, D, E, K) so your body can use them!
Essential fats like omega-3 and omega-6 are needed because our body cannot make them. They help with brain development, controlling inflammation, and blood clotting.
Provides texture, aroma, mouthfeel to our food
insulation and padding to keep us warm and protect our organs
Delays gastric secretion (slows things down)
Types of Fat - good, bad, in-between
Each type of fat has a similar structure - a chain of carbon atoms bonded to hydrogen atoms. What makes one fat different from another is the length and shape of the carbon chain and the number of hydrogen atoms connected to the carbon atoms. Seemingly slight differences in structure translate into crucial differences in form and function. (1)
Trans Fat - the kind you should avoid. Trans fats are hydrogenated - meaning that hydrogen atoms are added to healthful oils to make them solid at room temperature. They are hydrogenated to increase their shelf-life and are abundant in margarines/shortenings, processed foods, pastries, and other shelf-stable items. They are inflammatory and lead to chronic diseases/conditions.
Saturated Fat - the IN BETWEEN. Saturated fats are solid at room temperature and commonly found in dairy products, meat, butter, lard and some plant oils like coconut oil. Most recent studies have found that replacing these with vegetable oils and high-fiber, complex carbohydrates can actually reduce risk of CVD, however if replaced with refined carbohydrates, the opposite can occur.
*TAKEAWAY - these are fats to limit but recent research suggests there are worse foods for your cardiovascular health (refined carbs/added sugar). Choose grass-fed, organic versions of meat/dairy when possible as these foods still have other health benefits beyond their fat content!
Monounsaturated Fat - “Mono” means these fats have 1 double bond - which means there are two less Hydrogen atoms, making them different than saturated fats and liquid at room temperature. Find these in olive oil, canola oli, avocado, many nuts and seeds.
Polyunsaturated Fat - “Poly” means these fats have 2 or more double bonds - which means they are also liquid at room temperature and have even less hydrogen atoms. These are essential - meaning your body cannot make these and they must come from your diet! Both types offer many health benefits, but omega-3 fats are not as widely available in the American diet. Most of our food products and cooking oils are omega-6 - so aiming to get a good balance of both is important in the diet!
Omega 3: fatty fish (salmon, mackerel, tuna), walnuts, flaxseed, unhydrogenated soybean oil
Omega 6: vegetable oils including safflower, soybean, sunflower, walnut, and corn oils
Lets go back in the History of Fat…
For MANY years, foods high in fat (namely saturated and trans-fats) have had a bad rep in the food industry. The reason being - many studies had showed that saturated and trans fats increased the risk of Cardiovascular Disease (CVD) and the thought was that decreasing overall fat intake (which is higher in calories per gram than carbohydrates & protein) would lower our caloric intake and lead to weight loss.
HOWEVER, these thoughts drove food production and marketing to a “low-fat” CRAZE as I like to call it. Foods were then made with more refined carbohydrates and more added sugar and our healthier fats were avoided (nuts, seeds, avocados, oils).
Now in the nutrition world - good fats are getting more publicity and awareness. The focus being on “healthier” fats vs. not so healthy or even bad fats. Trying to include omega-3 rich fats (fatty fish like salmon, mackerel, walnuts, flaxseed) and omega-6 in a 1:1 ratio as well as monounsaturated fats like olive oil, avocados, nuts, seeds over the more saturated kinds of fats is found to be beneficial. In addition, reducing the amount of refined carbohydrates and added sugars compared to saturated fats has showed promising results.
Other articles talking about dairy fats and full-fat vs. low-fat choices bring up the point that dairy products (though higher in saturated fat than other plant-sources) contain other types of fat (mono and poly unsaturated) as well as vital vitamins and minerals (calcium and vitamin D) - and that most research is on single nutrients vs. an actual food product itself. Though research is inconclusive now on saturated fat, it is clear that there are healthy fats to consume (mono and poly-unsaturated fats) and unhealthy fats to avoid (trans fats).
In the media now where everyone and their mother are “nutrition experts” - it is important to go back to the science and literature on these claims. The most important thing is that you ARE consuming fat - because your body needs it and that you try to incorporate the beneficial fats such as mono and polyunsaturated kinds. That being said - if you have an item that likely has trans-fats, IT IS OKAY. The most important thing is to aim for a variety in your diet, satisfy yourself with foods and provide yourself with gentle nourishment.