Understanding Fat

The Role of Fat in the Diet

For as long as I can remember, I was told, "Fat makes you fat." Many popular diets are based on drastically limiting fat intake in order to induce weight loss. Cutting out fat is not easy, and like any lifestyle change, can be challenging. As you look for changes to make in your lifestyle, don't lose sight of the goal.

Low-fat eating is not an end in itself; it's just one part of the road to good health. Reducing the fat content alone does not guarantee good nutrition. Fruits, vegetables and fat-free cookies (still high in carbs and calories) are all low in fat, but they are not nutritionally equal. To reach the true goal of good health, many nutritionists recommend aiming for an eating approach that resembles that of the American Institute for Cancer Research's "New American Plate." By filling our plates primarily with more low-carb vegetables and fruits, we not only limit our fat intake, but also get the many nutrients and phytochemicals that help prevent cancer and promote overall health.

Low-fat eating is not an end in itself

Remember that protein and carbohydrates have 4 calories per gram, while fat has a whopping 9 calories per gram. In order to get rid of accumulated fat from our bodies, we have to expend more energy and/or reduce the amount of fat that we eat. Some fat is needed in the diet in order to:

• Transport and store certain vitamins and build hormones
• Enable the organs to function properly
• Promote normal brain function
• Provide energy and supply linoleic acid (an essential fatty acid) that the body doesn't make on its own
• Provide taste and texture to foods and help keep you satisfied longer
• Help curb the appetite
• Help store energy for when it may be needed (e.g. illness, fasting, etc.)

Nuts, oils and other fatty foods, such as fish oils, are a good dietary source for vitamin E, which as an antioxidant helps to protect cell membranes. These have proven to be beneficial in preventing and/or reducing the risk of heart disease and some cancers. Many fat-soluble vitamins, either those taken as nutritional supplements and/or those found in many vegetables, are better absorbed when combined with small amounts of healthy oils.

What Kinds of Fat Are There?

Fats are not created equalFats are not created equal. They are divided into three categories: saturated, polyunsaturated and monounsaturated. All vegetable oils and animal fats are made up of fatty acids, and all oils and fats contain all three fats. The percentages range widely, from coconut oil with 92 percent saturated fat to macadamia nut oil with 81 percent monounsaturated fat. Animal fats and tropical oils are high in saturated fats and are solid at room temperature, while monounsaturated and polyunsaturated fats are liquid at room temperature.

Saturated: The fat to curb the most. Foods rich in saturated fat include butter, poultry skin, fatty meats, tropical oils (palm kernel, coconut and cottonseed), whole milk and high-fat dairy products. Saturated fats can raise the body's LDL ("bad") cholesterol, which is thought to produce arterial plaque that clogs the arteries.

Polyunsaturated: This is preferred, with limitation. It can be beneficial in lowering LDL ("bad" cholesterol). However, it can also lower HDL (the "good" cholesterol), which removes bad cholesterol and clears it from the body.

Foods rich in polyunsaturated fat include higher-fat fish such as herring (high in sodium and calcium), salmon and mackerel (high in essential omega fatty acids), anchovies (high in sodium), and sardines (high in calcium), as well as margarine (a trans fat – see below).

Monounsaturated: This is the preferred fat. Foods rich in monounsaturated fat include avocados, canola oil, olives and olive oil, peanut oil and most nuts. Many medical researchers and doctors are now recognizing these fats as being beneficial in lowering LDL cholesterol levels without lowering HDL cholesterol levels.

This decreases the risk of arterial plaque formation. Many medical experts believe that these fats actually reduce the risk of heart disease and stroke.

Trans Fats

These occur when liquid oils undergo the process of hydrogenation in order to make a harder, more spreadable margarine with a longer shelf life. Hydrogenated oils are also found in many processed foods (e.g., pretzels, crackers and cookies). Even though the original oil may have started out as a polyunsaturated fat, hydrogenation turns it into a more saturated fat. Trans-fatty acids have the same effect on blood cholesterol as saturated fat. In order to reduce the amount of trans fats in the diet, choose reduced-fat (light) margarine, soft-tub margarine, and margarines with water or liquid vegetable oil listed as the first ingredient.

Choosing Your Oil

All oils have about the same number of calories Any oil that contains less than 20 percent saturated fat is good for you when part of a balanced diet. All oils have about the same number of calories – 120 per tablespoon – but the more recommended oils (high in monounsaturated fat) are olive, canola and peanut. Other acceptable oil choices include grapeseed, walnut, safflower, sesame, soybean and sunflower.

While dietary cholesterol is a valid concern, remember that it is not found in any vegetable products. Only high-fat dairy products and animal fat contain cholesterol. Moreover, some people with a high-cholesterol problem are not helped significantly by reducing their dietary cholesterol. Many people on low carb diets, who eat higher amounts of fats, have seen their cholesterol and other lipids (fats) drop significantly. This is one of the strongest factors behind the theory of low-carb diets. People also feel that fats keep them satisfied longer than carbs.

Olive Oil

There's nothing confusing about the benefits of olive oil – it's tasty, loaded with "good" (monounsaturated) fat, and known to help lower LDL "bad" cholesterol. However, when you go to the store to buy a bottle of this liquid gold, you may be bombarded with a variety of types and colors. The type of olive oil recommended throughout this book, unless otherwise specified, is extra-virgin and cold-pressed. Olive oils do not differ in the types or amounts of fats they contain. The differences lie mainly in the taste and aroma. Here's the breakdown:

Extra-Virgin, Cold-Pressed Olive Oil: This is the highest quality oil, with the lowest acidity – 1 percent or less. With this type of oil, you need only a small amount to enjoy the flavor. Chefs often use it on salads, with bread, or in soups and stews. Because of its low smoking temperature, it should not be used for frying.

Virgin Olive Oil: This is an intermediate quality oil with an acidity of 1-3 percent. Since you need more of it to enjoy the flavor, it may not be your best choice.

Ordinary Virgin Olive Oil: Not commonly found in American supermarkets, but if you come across it some day, you should know it's one of the lowest quality oils (with 3.3 percent acidity). Not great for most cooking, but still okay for frying.

Light Olive Oil: This is simply a designation used by companies to market a less flavorful, more acidic type of oil to diet-conscious Americans. The term "light" means lighter in color and fragrance, not less fat or calories. These oils are generally between 90-95 percent refined olive oil and 5-10 percent virgin olive oil. They have had their color, taste and fragrance removed by the refining process. This process also destroys the antioxidants and heart-healthy chemicals in the oil.

Olive oils differ greatly in taste from brand to brandOlive oil should have a pleasant aroma and a delicate, but distinctive, taste. Olive oils differ greatly in taste from brand to brand, depending on the country of origin and the batch. If you are new to the flavorful and distinct taste and aroma of olive oil, consider starting with small bottles in order to learn about and be able to choose the best taste for you and your family.

Low Carb vs. Low Fat: The Bottom Line

Two recent studies published in the Annals of Internal Medicine found that dieters on either a low-carbohydrate or a low-fat plan lose about the same amount of weight after one year. The studies showed that people with diabetes had better control of their blood sugar on the low-carb diet, but people following a low-fat plan lowered their cholesterol levels. Those on the low-carb plans lowered their lipid and cholesterol levels as well.

Another study in the Journal of the American Medical Association concluded that low-fat diets do not protect women against heart attacks, strokes, or breast and colon cancer. So what and how much should we eat? How can we combine the best of both these plans?

Instead of cutting out carbs or fats altogether, try putting the emphasis on choosing good carbs and good fats. Spread your calorie intake among the foods that will give you the best nutrition. And most importantly, control your portions. One of my earliest memories in my "diet history" was having drilled into my mind and psyche, "The more you eat, the more you want – the less you eat, the less you want." This has proven true to this day!

By avoiding processed carbohydrates, you'll kick your cravings and help keep your blood sugar levels steady all day. And as you choose healthy monounsaturated fats and avoid saturated and trans fats, you'll help lower your cholesterol and maintain a healthy weight.