Scott DouglasThe Editors of Runner’s World - Runners World Essential Guides: Weight Loss: Everything You Need to Know about Running to Slim Down

Conventional dieting wisdom doesnt work for runners. It leaves you hungry, tired, and... overweight. So we updated popular weight-loss strategies to meet a runners needs. Youll learn how to fuel up smarter (on real food), run stronger, and drop pounds for good.

Though the fat-free craze peaked in the 90s, many dieters still avoid oils, butter, nuts, and other fatty foods. Their logic: If you dont want your body to store fat, then dont eat fat. Many dieters also know that one gram of fat packs nine calories, while protein and carbohydrate both contain just four calories per gram. Dieters can stretch the same number of calories a lot farther if they eat mostly carbs and protein in place of fat.

But the notion that having fat in your diet isnt a bad thing is catching on again. I think its a pretty antiquated thought now that we need to eliminate fat to lose weight, says Jonny Bowden, Ph.D., author of The 150 Most Effective Ways to Boost Energy Naturally . In fact, studies have shown that eating moderate amounts of fat can actually help you lose weight. The key is to make sure youre eating the right kinds. Saturated and trans fats are unhealthy because they raise your levels of LDL (so-called bad cholesterol). Trans fats may also lower your HDL (or good cholesterol) levels and increase your risk for heart diseasenot to mention weight gain. But unsaturated fats (which include mono- and polyunsaturated) have important benefits. Heres why runners should include these fats in their diet.

Keep You Satisfied: Unsaturated fats promote satiety, reduce hunger, and minimally impact blood sugar. Thats important because if your blood sugar dips too low, you may experience cravings, brain fog, overeating, and low energy, making it fiendishly difficult to lose weight, says Bowden.

Protect Heart Health: Unlike trans-fats, monounsaturated fats found in vegetable oils (such as olive and canola) and avocados have the added power to help lower LDL and reduce your risk of heart disease.

Reduce Injury: Unsaturated fats can help stave off injuries, such as stress fractures. A 2008 study in the Journal of the International Society of Sports Nutrition found that female runners on low-fat diets are at increased risk of injuryand a sidelined runner cant burn as many calories.

Decrease Joint Pain: Bowden adds that omega-3 fatty acidswhich are a type of polyunsaturated fat found in fish (particularly in salmon), walnuts, and ground flaxseedpossess anti-inflammatory properties that can help soothe knee, back, and joint aches and pains that plague many runners. Translation: Youll hurt less and run more.

Caloric Common Sense

Youve probably heard of the 500 Ruleslash 500 calories a day to lose one pound a week (one pound equals 3,500 calories). Its a nice, clean rule, says sports nutritionist Barbara Lewin, R.D, and for a lot of dieters, cutting 500 calories a day will help them lose weightat least for a while. The problem for runners, though, is that slashing that many calories can be too muchespecially if youre training hard. Cutting too many calories can be your worst enemy, says Lewin. It can lead to plummeting energy levels. You might not be able to work out as well or maintain muscle massyoure setting yourself up for failure. So rather than cutting 500 calories, runners should work to identify the number of calories they personally need to eat to lose weight, says Lewin. Heres how to find that number.

1. Count Calories: Track your intake by keeping a detailed food journal for one week, says Lewin. Write down everything you eat and note your energy and hunger levels on a scale of 1 to 10 (www.nutritiondata.com and calorieking.com provide calorie counts for most foods, making it easy to do the math).

2. TrimDont Slash: Start by cutting about 300 calories a day, says Leslie Bonci, M.P.H., R.D., director of sports nutrition at the University of Pittsburgh Medical Center. Its a more doable number and is more likely to reflect a drop in body fat. As long as youre running, youll still hit a 500-calorie deficit per day and lose about one pound a week.

3. Tweak It: If you cut 300 calories and maintain your energy levels, but the number on the scale hasnt budged, its time to reduce your intake gradually, says Bonci. You can also adjust for training. Racking up miles for a marathon? Add calories back in. Having an easy week? Reduce your intake further.

Small Changes, Big Rewards

You dont need to make drastic adjustments to your calorie intake to start dropping pounds. Small substitutes here and there can add up and lead to major weight loss. Jennifer Ventrelle, R.D., owner of a private weight-loss practice in Chicago called Weight No More, suggests these simple food swaps for a day of meals to help cut calories while keeping your energy levels high.

Swap Out: Bagel with cream cheese 360 calories

Swap In: Whole-grain bagel with peanut butter and a cup of yogurt 325 calories

Swap Out: Starbucks Grande Latte 190 calories

Swap In: Starbucks Grande Skinny Vanilla Latte 130 calories

Swap Out: Clif Bar 250 calories

Swap In: High-fiber, high-protein granola bar, such as Kashi GoLean Crunchy Bar 180 calories

Swap Out: Subway six-inch roast-beef sandwich on white with mayo, cheese, and veggies 400 calories

Swap In: Subway six-inch roast-beef sandwich on wheat with mustard, no cheese, extra veggies, and apple slices on the side 340 calories

Swap Out: Four-ounce pork chop and salad with apples, walnuts, and goat cheese 485 calories

Swap In: Four ounces of pork tenderloin and a mixed green salad with apples and walnuts (hold the cheese), and a half cup of brown rice 380 calories

Swap Out: One cup of vanilla ice cream 290 calories

Swap In: Half cup of vanilla ice cream with one cup of raspberries 205 calories

Original Daily Intake: 1,975 calories

New Daily Intake: 1,560 calories

Total Daily Savings: 415 calories

Many dieters walk the aisles of the grocery store feeling more anxiety than pleasure. They want to buy foods that will help them lose weight, provide nutrients, and make it easier to practice portion controlbut arent sure what to choose. So they gravitate toward foods that make those promises, honing in on products that are part of a weight-loss program or feature words like light, low-fat, reduced-calorie, diet-friendly, or low-carb. People think they need a certain diet program or diet products to be successful, says Elaine Magee, R.D., author of the book Food Synergy and the national newspaper column The Recipe Doctor, and these foods promise success.

But all too often, the opposite is true, says Magee. Runners can accomplish the same weight-loss goals while eating whole, real foods that taste better, provide more nutritional value, and are more satisfying. When you go for healthy whole foods, says Joy Bauer, R.D., author of Joys Life Diet: Four Steps to Thin Forever , such as lean proteins, boatloads of vegetables, fresh fruits, whole grains, nuts and seeds, and low-fat dairy, you tend to get satiated on the right amounts. That means it will be easier to keep portions under control and gauge how many calories youre taking in. Many dieters also end up feeling deprived because they think they have very few choices, says Magee. But when you realize that you have a nearly limitless range of healthy, whole foods, that feeling fades awayalong with the desire to overindulge.