Fats fall into two main categories: saturated and unsaturated. Saturated fats are solid or semi-solid at room temperature and are generally of animal origin. They include butter, lard, red meat, dairy products and palm oil. Most of us know they’re the fats we should be limiting in our diet.
Those with diets high in animal fats tend to have higher rates of increased cholesterol, heart disease, type 2 diabetes and certain cancers.
Unsaturated fats make up the other main category. In general, unsaturated fats are healthy fats when eaten in moderation. There are two main types of unsaturated fats, monounsaturated and polyunsaturated. A healthy diet should contain some of each.
Monounsaturated fats are found in olive oil, canola oil, avocados and nuts. They help lower LDL (the “bad” cholesterol) and increase levels of HDL (the “good” cholesterol).
Polyunsaturated fats include both omega-3 and omega-6 fatty acids. Omega-6s are found in sunflower, corn and soybean oil. They’re the polyunsaturated fats we tend to eat most of.
Omega-3 fatty acids are a special type of unsaturated fat. They promote heart health and fight inflammation in the body plus they help the central nervous system and eyes stay healthy. Omega-3s are found in fatty fish like salmon, as well as in flaxseed oil and nuts, especially walnuts.
Experts now believe that a healthy diet should contain at least 90 percent of fats eaten each day from a combination of unsaturated fats. Most Americans eat far fewer omega-3 fats than omega-6 and, according to health experts; they should make an effort to get more omega-3s.
Trans Fats: The New Bad Guy
Over the past few years we have seen the addition of a new and harmful player on the fat scene: trans fat. Developed by the food industry to improve the taste, feel and shelf life of packaged foods, trans fats have oozed into every corner of modern life. They are polyunsaturated fats that have been made into trans monounsaturated fats.
Although natural monounsaturated fats such as olive oil are good for you, trans fats are bad: they raise cholesterol levels, clog up arteries and damage blood vessels which can all lead to an increase in heart attacks.
Trans fats are found in thousands of grocery store products and fast food items, including cookies, crackers, margarines, cakes, granola bars, French fries, chips, salad dressings, candy, cereals and microwave or movie popcorn.
Look on labels for “hydrogenated” or “partially hydrogenated” oils. That means the product contains trans fat and should be avoided or eaten sparingly.
Fats and Weight Control
All fats have nine calories per gram, making fat an energy-dense food. We all know that eating too much fat will make us gain weight. But eating too little fat is not the answer either. Scientists believe that fats can actually help with weight loss.
Fats take longer to digest than either protein or carbohydrates, making us feel fuller longer.
As well as keeping weight under control, eating moderate amounts of fats and choosing the right kind of fats can protect us from many diseases.
Saturated fats are linked to high blood pressure and to secondary problems including eye damage, vision loss and stroke.
A number of studies also show that a diet high in saturated fat significantly raises the risk of Alzheimer’s disease, a disease that affects a person’s memory. A high-fat diet is also believed to be responsible for the much higher rate of colon cancer.
Changing eating habits is a slow process, but you can make major improvements in your diet by cutting back on saturated and trans fats and instead eating moderate amounts of unsaturated fats, paying close attention to sources rich in omega-3s.
Start by substituting fish for meat a couple of nights per week, avoiding fried foods and cutting back on prepackaged items. Read food labels, looking out for hydrogenated and partially hydrogenated oils, and select a healthy margarine to use as a spread. Many of the soft tub and liquid margarines are trans fat free. Use a little olive or canola oil when making salad dressing or for cooking. Sprinkle nuts on salads or cereal and substitute a small handful of peanuts for a handful of chips when you want a quick snack. Instead of cookies for dessert, try a piece of fresh fruit or a fruit salad.
The key to a healthy diet is being able to tell the difference between the good fats that are our friends from the bad fats that clog arteries and lead to obesity. When it comes to fat, recognizing the enemy is half the battle.
Tana Necsary, PharmD
