Fats: Good vs. Evil

We need fat, but there's a difference between butter and margarine.

April 30, 2010

One pound of stored body fat converts into enough energy to fuel a six-hour spin. Even the most sinewy pro stockpiles about 31,500 calories' worth of endurance energy in the form of fat.



Fat helps us absorb essential antioxidant vitamins such as A, D, E and beta-carotene, as well as vitamin K. Our bodies use it to build nerve tissue and to produce hormones such as estrogen and  testosterone. Without enough fat, we'd be sickly and slow. Too much, however, especially the wrong kind, can also make us sickly and slow.


"Endurance athletes, such as cyclists, are very efficient at using the fat stored in their muscles, so keeping those stores stocked is essential for performance and recovery," says Carmichael Training Systems sports nutritionist Kathy Zawadzki, coauthor of Food for Fitness: Eat Right to Train Right. But, she says, you don't want to eat so much calorie-rich, fatty food that you start putting it away in other places—like your gut. Also, not all fats are created equal, and when it comes to health and exercise performance the quality of fat you eat is just as, if not more, important than the quantity. Heart-healthy fats keep your cholesterol in check, and may even raise your protective HDL levels, while others increase "bad" LDL cholesterol and clog your circulatory system.


Your goal: Eat enough of the right kinds of fat to stock your muscles without getting it stuck in your arteries or around your waist. Here they are, from best to worst.


The fats that come from plants and fish are good. They slide through your arteries without gunking up the works. There are two varieties. Your number one choice is monounsaturated. These fats lower LDL cholesterol while raising or maintaining HDL. Great sources: nuts, avocados, olive oil and canola oil. Polyunsaturated fats are also generally healthy, but they slightly lower HDL levels, so they're considered a small step down. Prime sources:_ seeds, most vegetable oils (corn, sunflower, soy) and fatty fish such as salmon. Omega fatty acids (omega-3 and omega-6) fall into this category. Most health experts agree that we get too much omega-6 (mostly from vegetable oils) and not enough omega-3 (fish and flaxseed). So go easy on foods from the fryer and eat more from the sea.


These fats are less healthy, but not all bad. Mainly animal fats, they're found in meats and dairy foods such as burgers, butter, lard and cheese. (Coconut oil is saturated, too, but scientists say for unknown reasons it acts more like an unsaturated fat in your body.) Some saturated fatty acids may actually improve your cholesterol profile, but on the whole they tend to raise your heart-disease risk, so it's best to keep your consumption of them in check.


Evil. Forget the "there are no bad foods" BS and get these out of your diet. Trans fats occur in very small amounts in nature (mostly in animal foods), but for the most part are a product of food processing that solidifies vegetable oils. Trans fats are found in fried, processed and packaged foods such as crackers, cookies and chips, as well as in shortening and margarine, and have been linked to heart disease. Read your labels and steer clear of buying or eating foods that contain trans fats. Note: A food can contain up to half a gram of trans fat and still be labeled as containing zero. To know if you're about to buy or eat something evil, look for the words "hydrogenated" or "partially hydrogenated" on the ingredient list. And as a general rule, avoid eating these foods as much as possible.


YOUR ACTIVE ALLOWANCE: A Daily Approach To Fat Intake
Fat is calorie dense and stores easily, so a little goes a long way. To get the benefits without the bulge, experts recommend capping your daily fat intake at about 30 percent of your total calories. So an active cyclist eating 2,000 to 2,500 calories a day can eat up to 600 to 750 of those calories from fat. That's about 65 to 80 grams, one-third to one-half of which should come from plant foods, with the rest coming from lean meats and low-fat dairy. Here's a snapshot menu of a good-fat day.


6 ounces orange juice 0 grams fat
2 eggs, scrambled 10g
2 pieces toast w/ 2 pats butter 3g


Midmorning snack
8 oz. low-fat yogurt 3.5g


Tuna sub (1 can) w/1 tbsp. light mayo 21g
Salad w/1 tbsp. olive oil & vinegar 7g
8 oz. skim milk 0.56


Midafternoon nibble
1 oz. nuts 14.5g


4 oz. chicken breast 4g
1*2 to 1 cup mixed vegetables 0g
3 to 4 small roasted potatoes 1g


After-dinner treat
2 tbsp. peanut butter on 1 piece toast 16g


Grand total: 71.5 grams