You may have seen some bad press surrounding dietary fats, but how much of it is true? Fats are an essential part of our diet, particularly when it comes to absorbing other vital nutrients and helping our bodies function properly. The difficulty is that not all fats are created equal, and when it comes to unsaturated versus saturated fats in particular, there are a few things to consider.
In general, unsaturated fats like avocado, olive oil, nuts and seeds are the ‘good’ fats we want to include in our diet. These help support heart and brain health, among other functions. Saturated fat, on the other hand, should be consumed in moderation, with excessive levels associated with negative health outcomes.
Here, we will explain in more detail the differences between unsaturated and saturated fats and the functions they serve in the body. Also, if you’re looking for a nutrient-rich diet with lots of healthy fats, our guide to Mediterranean diet is a great place to start.
What is dietary fat?
dietary fat It is characterized as the fat that we consume from our food, differentiating it from body fat or triglycerides in the blood. It is one of the three macronutrients (protein, carbohydrates and fats) that are necessary for the essential functioning and function of our bodies.
All fats contain nine calories per gram, but not all fats are as nutritious as others. Polyunsaturated fats, particularly omega-3 and omega-6 fatty acids, are necessary for the proper functioning of our brain and body, while monounsaturated fats help us absorb fat-soluble vitamins, such as vitamins A, D, E and K. Some fats, such as saturated fats and trans fats, have been linked to negative health outcomes, including metabolic syndrome (a combination of obesity, diabetes, and high blood pressure) and cancer.
What is saturated fat?
Saturated fat is a single-bonded carbon chain that is saturated with hydrogen atoms, meaning it is generally solid at room temperature. While the hydrogenation process converts unsaturated fats into saturated fats (trans fats) by forcing hydrogen into the empty spaces in the carbon chain, saturated fats are naturally that way. While eating too much saturated fat can have negative health outcomes, consuming small amounts of saturated fat in moderation is fine, so you don’t have to completely cut out your favorite foods to avoid it.
Dr. Kevin Barrett, GP at new road surgery (opens in a new tab) in Hertfordshire, UK, further explains: “We need to eat some fat because it is important for the absorption of fat-soluble vitamins A, D, E and K, and is a source of essential fatty acids. Saturated fats in highly processed foods are associated with negative health outcomes, but those in less processed foods don’t have as strong links.”
Some sources of saturated fat include:
- fatty cuts of meat
- Processed meats, such as sausage or bacon
- Butter, butter and butter
- Hard cheeses, such as cheddar
- cream and ice cream
- Cookies, cakes and pastries
- Salty snacks, such as chips, crackers
- Fried food
- Coconut oil
Excessive consumption of saturated fat is one of the leading causes of obesity and related conditions in adults, according to a study from the International Journal of Molecular Sciences (opens in a new tab). With this in mind, it’s important to be mindful of how much saturated fat you’re consuming, as an estimated 70 percent of Americans consume more than the recommended daily amount, according to the USDA (opens in a new tab). On a 2,000-calorie diet, this equates to about 22 g of saturated fat per day.
Dr. Deborah Lee, of Dr. Fox’s Online Pharmacy (opens in a new tab), says that excessive consumption of saturated fats can lead to heart problems. “In general, saturated fats are ‘bad fats,'” she says. “These are the fats we should all be eating less of. They tend to be related to elevated bad cholesterol, and this increases the risk of atherosclerosis (the deposition of fatty plaques in the arteries), which causes heart disease, including heart attacks and strokes. In general, saturated fat should not represent more than 5-6% of the total daily caloric intake.
What is unsaturated fat?
There are two types of unsaturated fats: monounsaturated and polyunsaturated. Unsaturated fats can promote levels of ‘good’ HDL cholesterol in your body and lower levels of ‘bad’ LDL cholesterol, which can build up in your veins and arteries and cause high blood pressure.
monounsaturated
These fats come from plant sources and include:
- Olive and canola oils
- Nuts, nut butters, and nut oils
- avocados
- Seeds, such as pumpkin or sesame seeds.
A 2021 study in the nutrients (opens in a new tab) Journal indicates that consumption of monounsaturated fatty acids can lead to positive cardiometabolic outcomes. Another study in Annals of the New York Academy of Sciences (opens in a new tab) also found that promoting HDL (good) cholesterol can also reduce inflammation in the body, giving it potentially cardioprotective qualities. Because monounsaturated fats promote HDL (good) cholesterol, it’s important to make sure you get enough to maintain your heart health.
Polyunsaturated
These fats come from plant sources and include omega-3 and omega-6 fatty acids.
Sources of omega-3 include:
- Oily fish, such as mackerel and salmon.
- Eggs
- Seeds like flaxseed or chia seeds
- Nuts, such as walnuts.
- Legumes, such as soy.
“The omega-3 acids in oily fish are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid),” explains Dr. Lee. “Although the human body can synthesize EPA and DHA, it is not efficient at doing so, meaning levels tend to be low. Therefore, it’s important to make sure you’re getting enough omega-3s, either through your diet or by taking an omega-3 supplement. Omega-3 fatty acids are believed to help prevent the onset of heart disease by helping to lower triglyceride (blood fat) levels, lower blood pressure, and improve blood circulation.”
Sources of omega-6 include:
- Meat, fish and poultry
- Eggs
- Legumes, such as soy.
- Sunflower oil
- Corn
“Omega-6 fatty acids are essential fatty acids that are obtained from the diet and are primarily used to provide energy,” explains Dr. Lee. “The health benefits of omega-6s are less clear. It is recommended to eat more omega-3 than omega-6. Omega-6 is found in meat, poultry, fish, eggs, soybean oil, corn oil, walnuts, almonds, and cashews, for example.”
A review in the newspaper Biomedicine and Pharmacotherapy (opens in a new tab) tells us that omega-3 and omega-6 should be consumed in balance with each other. Omega-3’s are used to build our cell structure, and they are also important in keeping your immune system working properly. High levels of omega-6s may contribute to the development or worsening of cardiovascular disease, cancer, and inflammatory diseases, but when consumed in balance with omega-3s, they serve to lower harmful levels of LDL cholesterol, increase protective HDL, and help improve insulin sensitivity.
Unsaturated vs. Saturated Fats: Getting the Balance Right
the USDA Guidance (opens in a new tab) recommends that 20-35% of your total calories come from fat. This works out to around 44g to 77g per day on a 2,000 calorie daily diet. Less than 10% of your daily calories should come from saturated fat, 15 to 20% from monounsaturated fat, and 5 to 10% from polyunsaturated fat.
Dr. Lee is an advocate for Mediterranean diet, as it is low in saturated fat and high in unsaturated fat. “It may be that eating less saturated fat and more unsaturated fat helps increase your longevity,” she says. “People living in Greece and other Mediterranean countries, who have always had a high intake of unsaturated fats, have been found to have a lower risk of heart disease than those in other Western countries.”
For the best quality fats, opt for minimally processed liquid fats. For example, you should choose olive oil, which has been shown to have cardioprotective properties, instead of cooking with butter. Also, looking for healthier alternatives to unhealthy foods that are high in saturated fat can help you stay within your recommended daily limits.
Some healthy swaps you can make include:
| Unhealthy fatty foods | healthy alternatives |
|---|---|
| fatty cuts of meat | Lean meat, such as chicken or fish. |
| Processed meat like sausage, bacon | Lean meats, like chicken or fish (you can also get chicken sausage and turkey bacon, though these can be highly processed) |
| cream or ice cream | Greek yogurt or sherbet |
| Hard cheeses like Parmesan | feta or cottage cheese |
| Butter, lard, or lard | Olive oil, you can also use mashed banana or applesauce to replace fat in cooking. |
| Cookies, cakes and pastries | Fruit, granola, yogurt with honey |
| chips and cookies | Nuts and seeds, kale chips, homemade vegetables, or crispy tofu |
This article is for informational purposes only and is not intended to offer medical advice.
