In the diet fat is often made out to be bad. But the truth is that not all fats are created equal. Fat is a somewhat complex but completely necessary nutrient. Fat isn’t all bad. We need fat because it’s part of all our cell membranes, and it’s important to get a balance of different types of fat because it brings things in the body into a calmer state. Ideally, your diet will consist primarily of healthy fats – monounsaturated and polyunsaturated fats that are associated with better heart health. They’re found in vegetable oils such as olive oil, canola oil, sunflower oil, nuts and seeds, avocados and fish. But there are two other types of fats that you’ll encounter with your meals. Here’s what you need to know about saturated fat vs trans fat, how they differ, and why it’s best to avoid one or the other.
Trans Fat Vs Saturated Fat
The two types of healthy fats – polyunsaturated fats and monounsaturated fats – are liquid at room temperature because there is at least one double bond between the carbon atoms that form the backbone of the triglyceride molecule.
In contrast, the chemical structure of trans and saturated fats makes them solid at room temperature (think butter, lard and margarine compared to oil).
The research surrounding the adverse health effects of saturated fats is not as compelling as the research on trans fats. There is evidence that replacing saturated fats with foods containing unsaturated fats or carbohydrates can reduce the risk of cardiovascular disease.
However, while it was once thought that diets high in saturated fats were clearly associated with increased heart disease and all-cause mortality, subsequent studies have been less definitive, and some studies have even suggested that certain saturated fats – such as those found in coconut oil – may be beneficial to the heart.
Overall, while nearly all nutrition experts recommend unilaterally removing all trans fats from the body, some amounts of saturated fats can and should be included in the diet. In addition, even some foods that contain naturally healthy fats, such as salmon, contain some saturated fats.
What is Trans Fat?
Trans fats, also known as partially hydrogenated vegetable oils or trans fatty acids, are more harmful than saturated fats, Leben said.
Trans fats are a type of unsaturated fat that comes from natural or man-made sources. Naturally occurring trans fats are produced in the stomachs of ruminants (such as cattle and sheep) and can be found in certain meats and dairy products.
But most trans fats – the type you always hear about – are industrially manufactured. It is produced through a manufacturing process called hydrogenation. This is when hydrogen is added to vegetable oils, converting them to solid fats at room temperature. This process extends the shelf life of the product.
Until recently, trans fats were commonly found in packaged processed foods, such as:
- Frozen pizza
- Processed snack foods
- Pie crusts
- Stick margarine
What is Saturated Fat?
Saturated fats differ in chemical structure from polyunsaturated and monounsaturated fats in that there are single bonds between all carbon atoms that form the backbone of the triglyceride molecule and all other bonds are made with hydrogen atoms.
For monounsaturated fats, there is a double bond between carbon atoms, while for polyunsaturated fats, there are multiple carbon atoms with double bonds between them instead of single bonds.
The greater the number of double bonds, the more mobile or bendable the fat molecule is. This changes the way fats behave in the body and outside the body. This is why, for example, unsaturated fats are liquid at room temperature.
Saturated fats are mainly found in animal foods, such as red meat, poultry skin, egg yolks, pork and full-fat dairy products. Because butter is high in saturated fat, baked goods and fried foods are also high in saturated fat. There are some plant-based sources of saturated fat, namely coconut oil, palm oil and palm kernel oil.
In the United States, the major sources of saturated fat are pizza, cheese, whole and reduced fat milk, butter, ice cream, cookies and fast food dishes.
In light of conflicting evidence and considerable research showing that saturated fats are harmful when consumed in excess, the Dietary Guidelines for Americans recommend limiting your saturated fats to no more than 10% of your total daily calories.
For example, if you consume 2,000 calories per day, you should eat no more than 200 calories of saturated fat. Because there are 9 calories per gram of fat, this means you should limit your saturated fat intake to a maximum of 22 grams per day.
In addition, the American Heart Association recommends that your saturated fat intake should be no more than 7% of your total daily calories.
Overall, when it comes to trans fats and saturated fats, there are some similarities in that too much of either can be harmful to your health. That said, the evidence surrounding the dangers of saturated fats is mixed at best, while trans fats are known to be harmful to your health.