The War On Fats
The vilification of fats dates all the way back to the 1950s, when research and public health campaigns began to associate dietary fat (specifically saturated fat) with an increased risk of heart disease. In response, governments and health organizations pushed low-fat diets as a way to prevent cardiovascular issues. Food companies jumped on the trend, marketing “low-fat” and “fat-free” products as the key to weight loss and by the 1980s and 1990s, the anti-fat movement was in full swing. Grocery store shelves were suddenly packed with these so-called “healthier” options—most of which were loaded with sugar and processed fillers. The industry took off, and fat’s reputation was ruined forever (I’m being dramatic, but you get the drift).
Unfortunately, while the anti-fat movement was meant to improve public health, its narrow focus on cutting fat had some serious unintended consequences. As fat consumption in the U.S. declined, processed foods, trans fats, refined carbs, and sugar-filled snacks took their place. As a result, the prevalence of Type 2 diabetes shot up 166% from 1980 to 2012, a terrifying increase. Today, more than 98 million American adults—or about 1 in 3—have pre-diabetes, costing the healthcare system a staggering $413 billion per year. The war on fat didn’t just miss the mark—it left a negative lasting impact.
Even now, despite everything we’ve learned about nutrition, many people still see fat as the enemy, ignoring just how essential it is for overall health. In this post, we’re breaking it all down—debunking myths, exploring the different types of fat, and explaining their impact on the body. You’ll learn which fats support your health, which to avoid, and what the latest dietary guidelines actually say. I know this post is dense, but its also packed with valuable insights. Let’s get into it!
Introduction To Fats
Fats are one of the body’s primary energy sources, fueling everything from physical activity to cellular metabolism and organ function. They’re also the most energy-dense macronutrient, providing more than twice the calories per gram compared to protein and carbohydrates, making them the most energy-efficient macronutrient. For reference, the three primary macronutrients are protein, carbohydrates, and fats. Without enough fat in your diet, you’re more likely to feel sluggish, drained, and constantly hungry.
Beyond energy, fats play a critical role in nutrient absorption. Vitamins A, D, E, and K—essential for vision, bone density, immune function, blood clotting, and more—are fat-soluble, meaning they can’t be properly absorbed without dietary fat. Without enough fat, these key nutrients go to waste, increasing the risk of deficiencies and related health issues.
Fats are also fundamental to cell structure, helping to maintain the integrity of cell membranes and protecting vital organs with cushioning fatty pads. They regulate appetite, keep skin and hair healthy, and support brain function. Omega-3s in particular help manage inflammation, promote cardiovascular health, and play a major role in cognitive function.
For women, fat is even more essential. It’s directly tied to hormone production, menstrual cycle regulation, and reproductive health. Too little fat in the diet can disrupt hormone balance, leading to irregular periods, fertility issues, and even long-term metabolic dysfunction.
Fat is a powerhouse macronutrient, fueling the body, stabilizing energy levels, and preventing intense hunger crashes. It plays a vital role in overall well-being, supporting everything from hormone regulation to metabolism. Prioritizing the right fats can have a profound impact on weight management, cognitive function, and long-term health.
With fat playing such a crucial role in the body, understanding how to incorporate it into your diet is key to maintaining 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 further divided into two categories—monounsaturated and polyunsaturated. This section will cover saturated and unsaturated fats, both of which occur naturally in foods, while the next section will focus on trans fats, which are primarily artificial.
All foods that contain fat have a mix of saturated, monounsaturated, and polyunsaturated fats. However, one type is usually present in higher amounts than the others. This is important to pay attention to because the dominant fat in a food determines its overall impact on health. Understanding which types of fat are most concentrated in the foods you eat can help you make better choices for your diet.
Here's a useful rule of thumb for identifying the types of fats in foods: Animal fats tend to be high in saturated fats, while plant-based foods are mostly composted of unsaturated fats. Fish falls somewhere in between, offering a rich source of unsaturated fats—particularly polyunsaturated fats like omega-3s, which provide significant health benefits.
Monounsaturated and polyunsaturated fats, typically found in plants, nuts, seeds, and seafood, are generally considered healthier dietary choices than saturated fats. However, there are exceptions. Coconut oil, for instance is a plant-based fat but is high in saturated fat. The table above offers a clear breakdown of how different fats are distributed in various foods.
Saturated fats in certain foods remain solid at room temperature, making them easy to spot—think of the solid fat on uncooked bacon. However, in foods like cheese and butter, high amounts of saturated fat are present but not as visually obvious.
On the other hand, unsaturated fats are typically liquid at room temperature, as seen in olive oil and avocado oil. While these visual differences can provide clues about a fat’s composition and properties, checking food labels is the best way to know exactly what types of fat a product contains.
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. In contrast, monounsaturated and polyunsaturated fats support heart health by helping to lower LDL cholesterol. You’ve probably heard of LDL (low-density lipoprotein) and HDL (high-density lipoprotein) cholesterol, but let’s take a moment to break them down.
LDL cholesterol is often called “bad” cholesterol because high levels can lead to plaque buildup in the arteries, increasing the risk of heart disease. On the other hand, HDL cholesterol, known as “good” cholesterol, helps clear LDL cholesterol from the bloodstream by transporting it to the liver, where it’s broken down and excreted. Higher levels of HDL cholesterol are linked to a lower risk of heart disease. You can read more about cholesterol on the American Heart Association’s site.
ven though saturated fats are known to raise LDL cholesterol and are often labeled as “bad,” there are always exceptions. Take beef, for example—it’s high in saturated fat but also contains significant amounts of heart-healthy monounsaturated fats. It’s also a great source of high-quality protein, iron, zinc, and B vitamins, all of which play essential roles in energy production, immune function, and muscle health. As I mentioned above, almost every food has a mix of both saturated and unsaturated fats, so it’s important to look at the bigger picture.
The real takeaway is that the health impact of fats depends on both the type and amount consumed. While both saturated and unsaturated fats have a place in a balanced diet, prioritizing sources rich in unsaturated fats—like olive oil, avocados, and fatty fish—can support heart health and lower the risk of chronic disease. At the end of the day, as cheesy as it sounds, balance is everything.
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 fats, commonly found in processed foods like cakes, cookies, donuts, and breakfast cereals, pose even greater health risks than saturated fats. In addition to being harmful on their own, they’re often found in foods high in refined carbohydrates and sugar, making them an even worse choice for overall health.
Trans fats raise LDL (bad) cholesterol while simultaneously lowering HDL (good) cholesterol, a combination that significantly increases the risk of heart disease. They have also been linked to inflammation, insulin resistance, and metabolic disorders, further contributing to long-term health problems. Unlike other fats, which may have some nutritional benefits in moderation, trans fats offer nothing beneficial to the body—only harm.
Because of these risks, health experts universally recommend minimizing or eliminating trans fats from the diet, along with the processed foods that contain them. We’ll cover these guidelines in more detail below, but the bottom line is: stay away from trans fats when possible.
Guidelines for Fat Intake
If you're wondering how much fat you should be eating each day, the answer is always the same: it depends on you. Fat intake is bio-individual, meaning it varies based on your unique physiology, lifestyle, and overall health needs. However, if you're looking for general guidelines, recommendations from the Dietary Guidelines for Americans, the Dietary Reference Intakes, and the American Heart Association can provide a helpful starting point.
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
Understanding how essential fats are, it’s clear that eliminating them entirely can have negative effects on our health. As emphasized throughout this post, prioritizing whole, unprocessed foods rich in healthy fats—like the monounsaturated and polyunsaturated fats found in olive oil, nuts, and fatty fish—is key. While saturated fats from animal products and certain plant oils should be consumed in moderation, they still have a place in a balanced diet. The real concern is trans fats, which are commonly found in processed foods and have been strongly linked to heart disease and other health issues.
To reiterate, for women, fat is particularly important. It plays a vital role in hormone regulation, supporting everything from reproductive health to mood stability and energy levels. A diet too low in fat can disrupt hormone production, leading to irregular cycles, fertility challenges, and imbalances that affect overall well-being. Making sure to include enough healthy fats can help maintain hormonal health, cognitive function, and sustained energy throughout the day.
By being mindful of the types and amounts of fats we consume, we can better support our health in a sustainable way. I hope this post has helped clarify the important role fats play in our diets. If you have any questions or want to dive deeper into any topic covered, feel free to reach out!
Stasia xx
