When you begin an exercise program like running, your body will want to replace those extra calories lost, which can make you hungrier and cause you to consume too many calories, explained registered dietitian Jessica Levings from Balanced Pantry.
Or you may have the mentality that because you worked out, you've "earned the cake, extra servings, or second glass of wine," as a reward, explained registered dietitian nutritionist Kristin Koskinen with Eat Well, Live Well. If you only burned 300 calories on your run and you consume an extra 300 calories, it makes sense that you wouldn't lose weight.
Jessica recommends making an appointment with a registered dietitian so he or she can help you design an individualized eating plan based on your calorie needs and weight goals. If you're unable to meet with an RD, use this formula to calculate your daily calories.
Many people think that eating a diet low in carbs and high in protein is the key to losing weight. But one common problem runners face, which leads to a lack of fat loss, is eating too much protein, explained Jessica. "The Academy of Nutrition and Dietetics and American College of Sports Medicine recommend 1.2 to 2.0 grams of protein per kilogram of body weight per day for athletes, spaced out throughout the day and after workouts," she said. "Anything extra will be stored the same way as any extra calorie — as fat."