Blog: Should I avoid dietary fat?

“Should I avoid fat in my diet?”

There is much confusion around dietary fats. We hear about “good fats” and “bad fats” and let’s not forget the ongoing battle between low-carb and low-fat diets. So, the next time your patient asks if they should avoid fat, don’t automatically say, “yes, you need to follow a low-fat diet.” Not all fats are harmful.

What is dietary fat?

Fats are essential for cell function, energy, organ protection, satiety, insulation and temperature regulation, hormone production and absorption of vitamins A, D, E and K. The major thing to focus on with fat is the quality. All fat is not created equal, so let’s break this down a little.

Different types of dietary fat

Fat can be categorized as saturated, unsaturated fats or trans-fat.

1. Saturated fats are solid at room temperature and are primarily found in animal products, like butter, fatty cuts of meat and cheese, but some plant foods are also high in saturated fats, like coconut, coconut oil, palm oil, and palm kernel oil. In the United States, our primary sources of saturated fat are:

• Pizza and cheese
• Whole and reduced fat milk, butter and dairy desserts
• Meat like (sausage, bacon, beef, hamburgers)
• Cookies and other desserts
• Fast food items

The Dietary Guidelines for Americans recommends getting less than 10 percent of calories each day from saturated fat and the American Heart Association goes even further, recommending limiting saturated fat to no more than 7 percent of calories.

Emerging evidence has shown that saturated fat is not as bad as we once thought, but the literature clearly shows that unsaturated fat remains the healthiest type of fat. Interestingly, cutting back on saturated fat will likely have no benefit if a person replaces saturated fat with simple carbohydrates. So be careful when telling your patient to limit their fat intake if you aren’t telling them what to replace it with. We want to encourage limiting saturated fat and replace it with polyunsaturated fats.

2. Unsaturated fats are commonly found in plant foods, like oils, avocados, olives, nuts and seeds. Unsaturated fats, which are liquid at room temperature, are considered beneficial fats because they can improve blood cholesterol levels, decrease inflammation, and stabilize heart rhythms. The American Heart Association recommends consuming more unsaturated fats than saturated fats, especially if you are at risk for heart disease.

Unsaturated fats can be further categorized into: monounsaturated and polyunsaturated

• Monounsaturated fats are found in:

• Olive, peanut, and canola oils
• Avocados
• Nuts like almonds, hazelnuts, and pecans
• Seeds such as pumpkin and sesame seeds

• Polyunsaturated fats are found in:
  • Sunflower, corn, soybean, and flaxseed oils
  • Walnuts
  • Flax seeds
  • Fish
  • Canola oil – though higher in monounsaturated fat, it’s also a good source of polyunsaturated fat.

I want to briefly discuss Omega 3s and omega 6s because they fall under polyunsaturated fats:

Fun fact if you want to geek out: The terms omega-3 and omega-6 don't signify anything special. They describe the position of the first carbon-carbon double bond in the fat's backbone. This influences the shape of a fat molecule which affects its function in the body.

The benefits of omega-3 are well known. They help protect the heart from arrythmias, ease inflammation, prevent clot formation and lower levels of triglycerides.

• Omega-3 Fatty Acids: Omega-3 fatty acids, such as ALA, EPA, and DHA, found in fatty fish, are crucial for brain development and function. They contribute to building cell membranes and affect cell receptor function, hormone production, and genetic regulation. These fats aid in preventing heart disease, stroke, and may alleviate conditions like lupus, eczema, and rheumatoid arthritis. Additionally, they exhibit protective effects against cancer and other ailments. Omega-3s reduce blood pressure, heart rate, and improve blood vessel function. Aim for 2 servings a week. Good sources include:
• Fish and other seafood (especially cold-water fatty fish, such as salmon, mackerel, tuna, herring, and sardines)
• Nuts and seeds (such as flaxseed, chia seeds, and walnuts)
• Plant oils (such as flaxseed oil, soybean oil, and canola oil)

Omega-3 dietary supplements include fish oil, krill oil, cod liver oil, and algal oil (a vegetarian source that comes from algae). They provide a wide range of doses and forms of omega-3s.

• Omega 6 fatty acid, another essential fatty acid, is found in safflower oil, sunflower oil, corn oil, soybean oil, sunflower seeds, walnuts, pumpkin seeds. You may have heard that these types of oils are “toxic” from some media headlines.

Their main issue is that the body can convert the most common omega 6 fatty acid, linolenic acid, into another fatty acid called arachidonic acid, and arachidonic acid is a building block for molecules that can promote inflammation, blood clotting, and the constriction of blood vessels. But the body also converts arachidonic acid into molecules that calm inflammation and fight blood clots, but a plethora of well-documented research shows that Omega-6 fats are not only safe but are beneficial for the heart and circulation.

Intake of omega-6 polyunsaturated fatty acids has been associated with lower risk of total death and death due to cardiovascular disease, cancer, and respiratory disease.

Most Americans eat more omega-6 fats than omega-3 fats, so encouraging a balance is a good idea by suggesting they add some extra omega-3s, rather than freak out about omega-6s.

3. Trans-Fats: These fats are made by heating liquid vegetable oils in the presence of hydrogen gas and a catalyst, a process called hydrogenation, which makes them more stable and less likely to become rancid. This process also converts the oil into a solid, which makes them function as margarine or shortening. They also can withstand repeated heating without breaking down, making them ideal for frying fast foods.

Partially hydrogenated oil can be found in margarine, vegetable shortening, Vanaspati ghee, fried foods, and baked goods such as crackers, biscuits and pies. Baked and fried street and restaurant foods often contain industrially produced trans fat. Trans fats are also naturally found in beef fat and dairy fat in small amounts.

Trans fats are the worst type of fat for the heart, blood vessels, and rest of the body. They have harmful health effects even in small amounts –for each additional 2 percent of calories from trans-fat consumed daily, the risk of coronary heart disease increases by 23 percent!

Trans-fats raise LDL and lower HDL, create inflammation, which can lead to heart disease, stroke, diabetes, and other chronic conditions and they contribute to insulin resistance.

So… when your patient asks about fats, suggest they eat as few trans and saturated fats as possible and focus on fish, nuts and seeds throughout the week!