During the long winter it's easy to fall into poor eating habits, when fresh, local produce is a distant memory and comfort foods become the norm. Making matters worse, your training likely tapered off during the colder months. If you've emerged from hibernation feeling lethargic and heavy, now is the time to spring-clean your diet.

But "spring-cleaning" doesn't mean restricting yourself to juice cleanses and detox fasts. "It's about going back to basics with whole, minimally processed foods that will prepare your body for the boost in spring training,"says Marni Sumbal, M.S., R.D., owner of Trimarni Coaching and Nutrition in Jacksonville, Florida. Freshen up your diet with easy changes that will kick-start your training and improve your health.

Cut Out Sugar
Cleaning up your diet starts with scouring your kitchen for items laced with added sweeteners. A 2013 report in the American Journal of Public Health followed nearly 5,000 men and women over 30 years and found that participants' calorie intake from added sugars increased by about 50 percent during that time period. As sugar consumption increased, so did waist measurements. "Sweeteners deliver empty calories and encourage overeating," says Chris Mohr, Ph.D., R.D., a sports nutritionist in Louisville, "both of which lead to weight gain." Too much of the sweet stuff has been linked to an increase in disease risk, including diabetes. Natural sugars in dairy, vegetables, and fresh or unsweetened dried fruit don't count as added sugars. But corn syrup, evaporated cane juice, dextrose, and other sugar impersonators in yogurt, cereals, granola bars, and even pasta sauces certainly do.

Scan ingredients on packaged foods and choose those with little if any added sweeteners. Replace sugary breakfast cereals, flavored yogurts, and reduced-fat peanut butter (which often swaps fat for sugar) with steel-cut oats, plain yogurt, and natural nut butter.

Go Raw
After a winter full of stews and roasted vegetables, you may be craving fresher-tasting raw foods—and that may help you lose weight. A 2011 study by Harvard scientists found that cooking increases the amount of calories your body absorbs from food. That's because heat breaks down cell membranes in food, making more calories available for absorption. It also makes digestion easier, so you don't burn as many calories digesting. The implication is that a serving of raw carrots and sashimi salmon may contain fewer calories than the same weight of roasted carrots and grilled fish. "Raw food requires extra chewing," says Mohr, "which gives your brain a chance to register fullness, so you're less likely to overeat, too."

Bolster your meals and snacks with more raw edibles. Top your (cooked) chicken or fish with a raw vegetable salsa. Replace flour tortillas with lettuce or collard greens. Snack on raw nuts and baby carrots. Top oatmeal and yogurt with berries. Cook pasta al dente and serve it with fresh tomato sauce with raw veggies like broccoli mixed in.

Choose Color
Sweep away the dull winter with spring's colorful fruits and vegetables. Eating a rainbow of foods is a great way to load up on fiber, vitamins, and other disease-fighting compounds. "The pigments that give fruits and vegetables their colors are vital antioxidants," says Sumbal. "Runners need these antioxidants to combat exercise-induced oxidative stress that can impact recovery." The more colors you eat, the better: Colorado State University researchers found that subjects who ate a wide variety of produce had lower levels of DNA oxidation than those who focused on a limited number of plant foods.

Include three or more colors in each meal and one or two colors in snacks. Scramble eggs with spinach and red bell pepper. Add strawberries and apricots to green salads. Brighten up sandwiches with shredded carrot and arugula. Blend blueberries into smoothies.

Drink Up
Drinking water during the colder months is not always appealing, so fluid intake tends to suffer. But with long runs in warmer weather on the horizon, it's time to take hydration seriously again. "Dehydration can impact your metabolism, leave you sluggish, and can mask itself as hunger," says Sumbal. But avoid drinking your calories: A University of Kansas Medical Center study found that post-meal hunger and the desire to eat were greater when subjects drank liquid calories compared to when they took in the same number of calories from food. Researchers found that levels of ghrelin, a hunger-boosting hormone, were higher in the liquid-calorie group.

"A good guideline for runners is to consume .5 to 1 ounce of fluid per pound of body weight each day," says Sumbal, "plus extra fluid during and after exercise." Replace sugary lattes and sodas with green or herbal tea, coconut water, seltzer, and unsweetened iced tea. "And load up on water-rich produce, such as lettuce, celery, and fruits," says Sumbal.

Get in the Kitchen
Eating at restaurants drains your wallet—and can add pounds to your waist. A University of Texas at Austin study found that dieters scarfed down 253 more calories and 16 extra grams of fat on the days they ate out. Even nutrition labeling on many restaurant menus isn't doing much to slash the calories we inhale, according to a study by University of Washington researchers. By prepping your own meals you can sidestep calorie bombs, improve portion control, and pack meals and snacks with nutrient-dense whole foods.

Create a weekly meal plan so you're less inclined to eat out or dial for takeout. Get excited about cooking again: Try a new recipe from a healthy cookbook or a visual potluck Web site like tastespotting.com. "Enroll in a cooking class with a friend," says Mohr. Buy a new kitchen gadget that you can't wait to try, or shop at a spring farmers' market for inspiring local ingredients.