Roadblock: You're not catching enough ZZZs.Research has linked sleep loss to obesity and suggests that people who don't get enough may weigh more. And a recent study in the American Journal of Clinical Nutrition found that people who get less sleep eat more snacks, especially high-carb ones. Without enough sleep, says Heather Gillespie, M.D., a sports-medicine physician at UCLA, your energy levels, immune system, and mood drop — the only thing up (besides you) will be your appetite. But that doesn't mean you should cut out your morning runs to stay in bed. Routine is key for weight loss, says Lisa Dorfman, R.D., director of sports nutrition and performance at the University of Miami. Consider going to bed an hour earlier or try switching your workouts to later in the day.
Roadblock: You eat energy-dense foods.A hamburger is an energy-dense food — meaning it packs more calories than less dense foods, like vegetable soup and a turkey sandwich. Less dense foods have a higher water content than fats and carbs, explain researchers in a 2007 American Journal of Clinical Nutrition study, which found that people who lower their energy density lower their weight. A more recent study from the same journal found similar results: Those who eat a lot of energy-dense foods weigh more, have a higher intake of trans and saturated fat, and eat fewer fruits and vegetables.
Fill up and fuel your body for better workouts with the healthiest diet for runners.
Roadblock: You're stuck in a color rut.Many runners get the majority of their calories from carbs all the time. "I call it the flu diet," says Dorfman. "Everything is bland and white." But research supports a colorful diet: A recent study published in the American Journal of Clinical Nutrition found that eating colorful berries twice a day for eight weeks helps lower blood pressure. "Eat at least five colors daily," says Dorfman. "so that you can be assured you're getting enough fiber and protein to help steady blood sugar and feel more satisfied after eating."
Roadblock: You only run.Running 15 miles a week burns roughly 1,500 calories—but to lose a pound, you need to cut 3,500 calories a week. Bottom line? Running alone won't cut it; if you want to lose weight more quickly, you need to adjust your calorie intake. In a study in the 2007 American Journal of Physiology, Endocrinology and Metabolism,, researchers followed participants for a year and found that lean and overweight adults who restrict their calorie intake by an average of 300 calories a day lose nearly 25 percent of their body fat. People who just exercise but don't eat fewer calories lose just over 22 percent. Both regimens worked, but your best bet is to combine the effort.
Discover Runner's World's 10 Rules of Weight Loss here.