The War On Fats

The vilification of fats dates all the way back to the 1950s, when influential research and public health campaigns began to associate dietary fat (specifically saturated fat) with an increased risk of heart disease. As a result, governments and health organizations began recommending low-fat diets as a means of preventing cardiovascular problems. This started the anti-fat movement, which gained even more momentum in the 1980s and 1990s. Taking full advantage of this emerging trend, food manufacturers launched marketing campaigns claiming that cutting fat consumption would also result in weight loss. Products labeled as "low-fat" or "fat-free" began to pop up in grocery stores across the country, and the industry took off.

Unfortunately, while the anti-fat movement aimed to improve public health, its singular focus on reducing fat intake had unintended consequences. As fat consumption in the US decreased, the consumption of processed foods, trans fats, refined carbohydrates, and sugary treats increased. As a result, the prevalence of Type 2 diabetes shot up 166% from 1980 to 2012 – a staggering amount. Today, approximately 98 million American adults—more than 1 in 3—have pre-diabetes, costing the healthcare system $413 billion per year. The effects of the “war on fats” have had a negative and lasting impact for decades. Even now, despite changes in nutritional understanding, many people still think that fats are harmful, overlooking their essential role in a healthy diet.

In this post, we're diving deep into the world of fats to clear up misconceptions and shed light on their impact on our health. We'll examine different types of fat, their health implications, recommended dietary guidelines, and which fats to include or avoid in your diet. It's an extensive read, but filled with valuable insights, so let's jump in!

Introduction To Fats

Fats are a major source of energy for the body, helping fuel physical activity, cellular metabolism, and organ function. Fats provide more than twice as many calories per gram when compared to carbs and protein, making them the most energy efficient macronutrient (as a reminder, the three primary macronutrients are protein, carbohydrates, and fats). Without enough fat in our diet, we might feel tired and sluggish.

Fats also play a crucial role in the absorption of fat-soluble vitamins such as A, D, E, and K, which are essential for maintaining healthy vision, bone density, immune function, blood clotting, and many other bodily functions. Without enough fat in the diet, the body will not properly absorb these vital nutrients, which can lead to vitamin deficiencies and associated health issues. Fats also act as structural elements in cell membranes, contributing to the maintenance of cell membranes integrity and proper functioning. Fatty pads surrounding vital organs provide protection from damage, and fatty tissues secrete enzymes and hormones that are involved in appetite regulation and the maintenance of healthy skin and hair. Certain types of fats, such as omega-3, are also important for regulating inflammation, supporting brain health, and promoting cardiovascular health. Fats play a thermoregulatory role, helping to insulate the body against extreme temperatures. Finally, fats contribute to satiety, helping to keep us feeling full and satisfied after meals. Including healthy fats in our diets can aid in weight management by reducing overall calorie intake and preventing overeating.

Given the many crucial roles fats play, understanding and incorporating them into our diets is essential for optimal health and vitality. However, just like carbs (which you can read about more in depth here), not all fats are created equal.

Below, we’ll dive into the different types of fats and the roles they play in our bodies.

Saturated and Unsaturated Fats

There are three main types of fat – saturated, unsaturated, and trans fats. Unsaturated fats are divided into two categories – monounsaturated and polyunsaturated fats. This section will focus on saturated and unsaturated fats, which are naturally occurring in foods. The section below will focus on trans fats, which are primarily man made.

The fat found in all foods will almost always be a combination of saturated, monounsaturated, and polyunsaturated fat. However, there will be a higher concentration of one of the three, and this is what you want to keep your eye out for.

Here's a useful rule of thumb for identifying the types of fats in foods: Animal fats tend to be rich in saturated fats, while plant-based foods are primarily composed of unsaturated fats. Fish, on the other hand, often boasts high levels of unsaturated fats, particularly beneficial polyunsaturated fats like omega-3. Monounsaturated and polyunsaturated fats, typically found in plants, nuts, seeds, and seafood, are generally considered  healthier dietary choices than saturated fats. However, exceptions exist. For instance, coconut oil, classified as a plant fat, contains substantial amounts of saturated fat. The table above provides a helpful visualization of this breakdown.

Saturated fats in certain foods retain a solid state at room temperature, making them visually distinguishable (picture the solid fat in uncooked bacon). However, other common foods like cheese and butter contain large amounts of saturated fat that are basically impossible to see. On the flip side, unsaturated fats are typically liquid at room temperature, like the fat in olive oil or avocado oil. Visual differences in fats offer clues about their composition and properties, but remember to check food labels to know exactly which fats are in a product.

Science Concept: The difference between liquid fats vs solid fats is a result of the presence or absence of double bonds in the carbon chain of these fats. The degree of saturation of a fatty acid has to do with the number of hydrogen atoms attached to the carbon chain. In a saturated fatty acid, carbon atoms are bonded to the maximum amount of hydrogen atoms possible. An unsaturated fatty acid occurs when there is at least one point (possibly more) of a fatty acid chain where a hydrogen atom can still bond with a carbon atom, but hasn’t. What this means in layman’s terms is that saturated fats are able to “stack,” making them more solid at room temperature. Unsaturated fats have double bonds that cause the carbon chains to bend, which makes it harder to “stack,” making these fats liquid at room temperature.

Health Implications of Saturated and Unsaturated Fats

When it comes to fats, saturated fats raise LDL cholesterol levels in the blood, which can increase the risk of heart disease. On the flip side, monounsaturated and polyunsaturated fats have a positive impact on the body by lowering overall LDL cholesterol levels. You may have heard of LDL (low-density lipoprotein) and HDL (high-density lipoprotein) cholesterol, but I’m going to take a second to break them down.

LDL cholesterol is often referred to as “bad” cholesterol because too much of it can lead to the buildup of plaque in your arteries and increase your risk of heart disease. In contrast, HDL cholesterol is often called “good” cholesterol because it helps remove LDL cholesterol from your bloodstream and transport it back to the liver, where it can be broken down and excreted from your body. HDL cholesterol is therefore associated with a lower risk of heart disease. You can read more about cholesterol on the American Heart Association’s site.

Even though saturated fats are known to raise your LDL cholesterol and therefore considered “bad,” there are always exceptions. One example is beef, which contains high levels of saturated fats, but also contains significant amounts of monounsaturated fats (remember, almost every food has both unsaturated and saturated fat in it). The key message is that the health effects of fats in foods depend on both the amount and type of fats consumed. While both saturated and unsaturated fats have a place in our diets, favoring sources rich in unsaturated fats, like olive oil, avocados, and fatty fish, can promote heart health and reduce the likelihood of chronic illnesses, contributing to a healthier lifestyle overall. As cheesy as it sounds, balance is always king.

Trans Fatty Acids - The Villain?

As previously noted, although trace amounts of trans fats can naturally occur in certain animal products like meat and dairy, the bulk of trans fats are primarily generated artificially via a process known as hydrogenation. In this process, liquid vegetable oils undergo treatment with hydrogen gas to transform them into solid fats. This process is commonly used in food manufacturing to improve the texture, shelf life, and flavor stability of processed foods. As a result of hydrogenation, unsaturated fats are converted into trans fats.

A great example of this is margarine. Margarine is made from vegetable oils. As you now know, vegetable oils are liquid at room temperature. To make margarine “spreadable,” these unsaturated fatty acids are partially hydrogenated, resulting in high levels of trans fats. Additionally, margarine products often contain artificial additives, preservatives, and colorings to improve flavor, texture, and shelf-life. They also lack the beneficial nutrients found in butter, such as fat-soluble vitamins A, D, E, and K. Despite being recognized as harmful to health, some companies still utilize trans fats in their products due to their ability to enhance texture, provide flavor stability, and extend the shelf life of products, ultimately prioritizing profit over consumer well-being.

Health Implications of Trans Fats

Industrially produced trans fatty acids, commonly found in products like cakes, cookies, donuts, and breakfast cereals, pose greater health risks compared to saturated fat. They are also considered unfavorable choices in terms of carbohydrate and sugar intake. This is because trans fats elevate LDL cholesterol and reduce HDL cholesterol levels, both of which are linked to heightened cardiovascular disease risks. Trans fats have also been associated with inflammation, insulin resistance, and various metabolic disorders. Unlike other fat types, trans fats not only raise LDL cholesterol but also lower HDL cholesterol, making them particularly detrimental to heart health.

Due to these health concerns, all health guidelines now advise minimizing or avoiding trans fats, as well as processed foods containing them, in the diet. We will cover these guidelines below.

Guidelines for Fat Intake

If you're curious about what your daily fat intake should be, the answer is always the same: it’s bio-individual. People’s needs will vary based on their unique physiology. However, for those seeking general guidelines, recommendations from the Dietary Guidelines for Americans, the Dietary Reference Intakes, and the American Heart Association provide some direction.

Dietary Guidelines for Americans

• Less than 10% of total calories per day should be from saturated fats; and

• Trans fats should be limited

Dietary Reference Intakes

• An Acceptable Macronutrient Distribution Range (AMDR) for fat intake is 20–35% of total calories (the upper end of this range is inline with the Mediterranean diet, which is high in fat);

• Calories from saturated fats should be restricted to less than 10% of daily intake (as per the DGA above)

American Heart Association

• Adults needing to lower their LDL blood cholesterol should reduce saturated fats in the diet to as little as 5%, in addition to lowering calories from trans fats

In summary, all three organizations recommend minimizing saturated fat intake, prioritizing unsaturated fats, and avoiding trans fats entirely or keeping their consumption to a minimum.

Conclusion

Realizing how important fats are, I hope you now see that completely cutting them out of our diets could lead to negative impacts on our health. As reiterated throughout this post, prioritizing whole, unprocessed foods rich in healthy fats—such as monounsaturated and polyunsaturated fats found in olive oil, nuts, and fatty fish—is key. While saturated fats, found in animal products and certain plant oils, should be consumed in moderation, they are still part of a balanced diet. Furthermore, it's important to limit or avoid trans fats, commonly found in processed foods, as they pose a heightened risk of heart disease and other health issues. By making informed choices about the types and amounts of fats we include in our diets, we can support our overall health and well-being.

I hope that this post has provided valuable insights and guidance on understanding the important role of fats in our diets. If you have any questions or need further clarification on any aspect discussed, please don't hesitate to reach out. Thank you as always for your support!

Stasia xx