While it’s not technically part of her job description, Dina Dugan, RD, a clinical dietician at Baystate Noble Hospital, finds herself regularly defending dietary fat.
“For years, fat has gotten a bad rap,” she says, “which is unfortunate as dietary fats are a necessary part of body composition. They provide energy, support cell function, and help with the absorption of certain vitamins. They even produce prostaglandins, a hormone-like substance that regulate vital bodily functions like blood pressure, inflammation, blood clotting, and pain.”
But, as Dugan is quick to note, not all fats are created equal. Understanding the differences between them is important for maintaining a healthy diet.
Types of Dietary Fats
“The tricky thing about dietary fats is that there are good fats and bad fats,” explains Dugan. “Understanding the differences between them helps you to make informed choices when deciding what to eat; choices that can actually reduce your risk of chronic disease.”
Common types of dietary fats include:
- Saturated
- Unsaturated
- Omega
Saturated Fats
Often referred to as “solid fats,” saturated fats are, in fact, solid at room temperature.
They are also the fat that many of us have been taught to steer clear of, and with good reason.
Found in animal-based foods such as meat, higher-fat dairy products (2% and whole), butter and ice cream, saturated fats can raise blood cholesterol and increase the risk of heart disease and stroke. Saturated fats are also found in some plant-based oils including coconut oil and palm oil.
While avoiding fats in meats is relatively easy—look for cuts of meat with little marbling or fat content, trim off excess fat when preparing meat for cooking, skip the skin on chicken, and simply don’t eat any fats found on prepared meats—it’s a little trickier when it comes to oils.
“The challenge with saturated oils is they’re present in so many of the foods we love,” says Dugan. “Palm oil especially is favored by food manufacturers because it’s inexpensive, it lends foods a creamy texture and taste, and it has a higher melting point. It’s in everything, from cookies, ramen, and ice cream to breakfast bars, chocolate, and margarines in both stick and tub form. It’s hard to avoid but doing so is important to your health.”
Further complicating the task of spotting palm oil on a label is the fact it may appear under many different names. Here’s a look at just a few of the ways it may appear:
- Vegetable oil
- Vegetable fat
- Palm kernel
- Palm kernel oil
- Palmitate
- Glyceryl
- Stearate
If you spot any of these names on a label, look for products that contain healthier oil options—like canola, soybean and olive oil—to help lower your risk of heart disease.
Unsaturated Fats
Liquid at room temperature, unsaturated fats come in both monosaturated and polysaturated forms. Often dubbed “good fats,” unsaturated fats offer a lot of benefits, including the ability to:
- Lower good and bad blood cholesterol levels
- Reduce inflammation
- Reduce the buildup of plaque in arteries
- Help your body absorb essential vitamins
- Improve heart health
Found mostly in foods from plants, these healthy fats are found in:
- Olive oil
- Peanut oil
- Avocado oil
- Canola oil
- Vegetable oil
- Flaxseed oil
- Nuts
- Seeds
- Fish
Omega Fats
Another type of unsaturated fat, omega-3 fats, are essential fatty acids. This means they must be taken in through the diet – the body cannot make them on its own. An extremely well-researched fat, omega-3s have been found to:
- Lower blood pressure
- Reduce risk of cardiovascular disease
- Reduce risk of blood clots
- Reduce risk of dementia and Alzheimer’s disease
“The key thing about omegas is that the only way to get them is by eating them, ideally on a daily basis,” says Dugan. “Excellent sources of omega fats include fatty fish, nuts, seeds, and even supplements. There are vegan-friendly supplement options available for vegans and those with fish and/or nut allergies.”
Trans Fats: Unsafe in Any Amount
Of all the fats, trans fats are the worst for your health. Too much trans fat in your diet increases LDL cholesterol levels and puts you at greater risk for heart disease and other health problems including prostate and colorectal cancer.
While trans fats are naturally occurring in animal products like meat and dairy, the amount found in those foods isn’t of great concern. The real concern is with manufactured, or artificial, trans fats in a process that adds hydrogen to liquid vegetable oils to make them more solid.
For years, artificial trans fats were very popular with food manufacturers and restaurants as they provided a less expensive way to prepare food, increased the shelf life of many products, and could be used repeatedly for frying.
Recognizing the huge health threat artificial trans fats posed, in 2015 the U.S. government ordered food manufacturers to stop using trans fats. The process of altering production, packaging, etc. was not easy but as of January 2021, all U.S. food manufacturers have complied with the order.
However, consumers may still see trans fats listed on food labels. In most cases the trans fat referenced is naturally occurring. And even if no trans fat is noted, trace amounts may be found in the product as any amount under 0.5g does not have to be listed.
How Much Fat Should You Eat?
While fats are necessary for a healthy diet, you need to be mindful of how much of each type you consume and the number of calories in fat.
“All types of fats provide 9 calories per gram,” explains Dugan. “Consuming them in moderation is crucial to prevent weight gain and related health issues.”
“In general,” she adds, “you should aim to get 20–35% of your daily calories from fat, and less than 10% of that should come from saturated fat. However, the recommendation of the American Heart Association for those with high blood cholesterol is to limit saturated fat to no more than 5% of your daily calories.”
To calculate your daily fat range, you need to multiply the number of calories you eat or want to eat by the recommended percentages and divide that by 9 (the number calories per gram of fat).
For example, if you eat 2,000 calories per day, your total daily fat in grams calculation will look like this: (2000 calories x 30%) ÷ 9 = 67 grams of TOTAL fat per day
The calculation for how the recommend daily amount grams of saturated fats will look like this: (2000 calories x 1%) ÷ 9 = 22 grams of SATURATED fat per day
“Once you’ve calculated that,” says Dugan, “it falls to you to track your specific type of fat intake by reading food nutrition labels and making wise choices. The good news is that many prepared foods now come in low-fat versions, which makes reducing saturated fat intake a little easier. As for when you’re cooking, choose unsaturated fats whenever possible and look to include omega-3 fats in your daily diet. The goal isn’t to eliminate fats entirely as our bodies actually need them. It’s to consume the best possible options for your health.”