Fat Gets a Bad Rap

Of the three macronutrients—protein, carbohydrate, and fat—fat is the most misunderstood. During the low-fat craze that began in the 1970s, all types of fat were avoided at all cost. In truth, certain types of fat are critical for hormonal balance, weight loss, brain health, and proper cardiovascular function.

The key is to understand the various categories of fat and how to incorporate them into the daily diet.

The many roles of fat

The inclusion of fats (also called fatty acids) in the daily diet is critical for overall health and wellness. Fats are a part of every cellular membrane in the body. Cell membranes are integral to the overall quality of health. They regulate the outside barrier that allows the transport of nutrients and glucose and protect against toxic exposure.

Fats also:

• build healthy brains: omega-3 fats provide structure to the myelin sheath in the brain
• keep arterial walls flexible and improve blood flow
• produce hormones: fats are structural components of some of the most important substances in the body, including prostaglandins, hormone-like substances that regulate many of the body’s functions
• help the body use vitamins such as A, D, E, and K, which are fat-soluble vitamins; fat in foods helps the intestines absorb these vitamins for use by the body
• promote antiaging and maintain healthy, beautiful skin
• form a protective cushion for our organs, especially the kidneys, heart, and intestines, to protect them from injury and hold them in place

The thumbs-up fats

Unsaturated fats are called good fats. This is because they can lower LDL (bad) cholesterol levels, ease inflammation, and may play a beneficial role in many other health systems.

Monounsaturated fats Monounsaturated fats are usually liquid at room temperature but start to solidify when chilled.

Healthy Sources: vegetable oils such as olive oil, peanut oil, and sesame oil; macadamia nuts; almonds; and avocados.

Polyunsaturated fats Polyunsaturated fats are usually liquid at room temperature as well as when chilled. Recent research shows that subjects who replaced saturated fat with polyunsaturated fat reduced their risk of coronary heart disease by 19 percent.

Healthy sources: vegetable oils, including soybean oil, corn oil, flax oil, and safflower oil, as well as fatty fish such as salmon, mackerel, herring and trout; and some nuts and seeds such as walnuts, flaxseeds, and sunflower seeds.

Essential fatty acids These are polyunsaturated fats essential for the body to function that cannot be made by the body and therefore must come from the diet. There are two main types of essential fatty acids: omega-3 and omega-6. The ideal ratio of omega-3 to omega-6 fatty acids in our diet should be between 1:2 and 1:4.

Unfortunately, the typical North American diet is critically low in omega-3 intake with a ratio of omega-3 to omega-6 ranging between 1:14 and 1:25. (See below for some simple tips to boost your omega-3 intake.)

• Omega-3 fatty acids are found in foods such as fish (and fish oils) including wild salmon, herring, sardines, rainbow trout, kippers, and mackerel as well as flax- seeds, flax oil, walnuts, and omega-3 enriched eggs.
• Omega-6 acids are found in foods such as soy and safflower oil; sunflower, pumpkin, and sesame seeds; nuts; and borage and primrose oils.

The thumbs-down fats

Saturated fats should be limited in the diet, and trans fats should be entirely eliminated.

Saturated fatsThese are typically solid at room temperature. Eating an excess amount of saturated fat can contribute to the development of high LDL (bad) cholesterol levels, high blood pressure, heart disease, and inflammation.

Unhealthy Sources: animal sources such as meat, poultry, butter, and cheese.

Trans fatsTrans fatty acids (TFAs) should be eliminated from the diet altogether. TFAs not only increase LDL (bad) blood cholesterol levels, they also lower HDL (good) blood cholesterol levels.

Unhealthy Sources: a small amount of TFAs naturally occur in meat and milk; however, the majority of harmful TFAs are found in packaged and procesed food souces.

TFAs have been shown to:

• raise the risk of coronary heart disease
• increase cholesterol
• promote the development of inflammation
• promote the development of Alzheimer’s disease
• increase the risk of type 2 diabetes
• increase the risk of obesity

They also may:

• raise the risk of certain types of cancers, such as breast and prostate cancer
• promote infertility

What about low-fat foods?

While opting for low-fat dairy products and lean meats is a good idea, do not mistake the claim of “low fat” by processed food manufacturers for healthy. Fats make food taste good and offer a satiating mouth feel or texture when consumed. When food manufacturers remove fat from an item and make a low-fat claim, oftentimes they add sugar to enhance taste.

Unfortunately, sugary foods that are labelled low fat are often high in calories. As a general rule, avoid cakes, cookies, muffins, and ice cream that are labelled low fat, and stick to healthy fat foods such as nuts, seeds, and avocados. If you want to indulge in a sweet, opt for naturally sweet foods such as fruits and dark chocolate.

How much fat is enough?

The Canadian Heart and Stroke Foundation recommends:

• Women should limit their total fat intake to 45 to 75 g per day.
• Men should restrict their intake to 60 to 105 g per day.
• Only 20 to 35 percent of our daily calories should come from fats.

While monitoring the amount of fat you consume is important, remember to choose good fats—your body needs them for optimal functioning.