Runners are drawn to rules. We like having exact workouts to complete, knowing our weekly mileage goals, and hitting our paces. We thrive on structure to get us across the next finish line. But when it comes to food, a little flexibility goes a long way.

While food rules may seem helpful at first, they lead to a diet mentality. Once food rules are developed, we’re putting ourselves at risk for nutrient and energy deficiency. We’re sticking to the regimen instead of listening to our body’s signals. As training progresses, energy needs change. If developing strength and fitness is the main goal, we’ll need ample nutrients and energy to make it happen! If health improvement through running is the main goal, we need to speak our body’s language to provide what it needs.

Letting go of, and altogether ignoring, food rules that weren’t made for you will help you learn how to fuel your body. So avoid or break these six common food rules and listen to your body to find out what you need to run at your best.

1. Always eat the same thing before a long run or speed workout.

In theory, this is a safe food rule for runners in training. There are going to be some foods that do not sit well with your gut the next day. You’ll know quickly when a certain meal or snack was the wrong choice for you. But, sticking to the same meal or snack every week may impede progress, too. Having an arsenal of options allows you to get in a variety of nutrients throughout your training cycle, and decreases anxiety if you’re traveling for a race and don’t have access to that exact food. The only reason I encourage runners to keep a general food log is to understand how different food choices play out during runs. It takes some trial and error to find what works well for you. Be open to a variety of foods, and be mindful of what definitely does not work.

2. Don’t eat past 8 p.m. or two hours before bedtime.

Diet rules have long suggested a cutoff time for evening eats. I often hear clients ask about meal timing around evening workouts, or how “unhealthy” it might be to eat right before going to bed. Kristen Chang, dietitian and certified specialist in sports dietetics (CSSD) based in Blacksburg, Va., notes, “It’s important to honor your hunger, even if that means eating before bed.” She adds, “a protein-rich snack at night has been found to positively benefit muscular recovery while you sleep!” So don’t ignore any evening hunger pangs, especially while training.

3. Count calories to refuel after a workout, or to monitor energy intake during the day.

There are a lot of guidelines around what to eat for maximum recovery after long or hard training workouts. One standard is to include both carbohydrates and protein in a post-workout meal or snack. Some athletes stress over how much is “too much” after their workouts, but Pittsburgh, Pa.-based sports dietitian Edie Shreckengast would rather focus on something besides those numbers: ”I ask my athletes, ‘How are you feeling?’” She suggests a “self-assessment” after refueling. Fatigue, trouble concentrating, headaches and irritability are all signs of underfueling. Rather than focusing on a calorie count, eat (a mix of carbohydrates and proteins, including some fat) until feeling full and satisfied.

4. Eat only low- or non-fat foods.

The fat-phobia of yore, along with its low- or non-fat food rule, lingers in many athletic fueling regimens. In an effort to be “lean” or focus on building muscle mass, fat may take a backseat. But fat is just as important to the diet as carbohydrates and proteins. “Fat supports a healthy immune system and fights inflammation,” notes Chang. It’s also a big factor in satiety, making meals and snacks more satisfying and keeping hunger at bay. All of the above are helpful—if not crucial–in supporting training and overall health goals.

5. Eat low-carb until the week(s) before your big race.

Low-carb diet trends span various sports, but long-distance runners and low-carb experiments rarely mix well, especially without professional guidance and intervention. The reason is simple: Carbohydrates are our body’s preferred fuel source for both the brain and muscles. Yet even in the absence of a formal diet, I see many athletes with a relatively low carbohydrate intake, until race week pops up. Then, it’s ALL about carb loading. “For high intensity training, exercising without adequate carbohydrate intake may not allow you to train well,” says Stephanie Saullo, a North Carolina-based dietitian with RITTER Sports Performance. With a low-carb mentality, runners may be more likely to ignore normal cravings and fall to a trend of under-fueling their training needs. “If you are underfueling, your performance will suffer,” adds Saullo. Eat enough, eat often, and eat a variety of foods that include carbohydrates, proteins, and fats.

6. Eliminate added sugars while training!

Added sugars are villainized in the post-fat-phobic age. Rather than moderating intake, detoxes, cleanses, and various diets suggest eliminating added sugars altogether. Treating one extreme with another is rarely effective. “Less restriction is more when it comes to optimizing athletic performance,” notes Chang. If you’re eating enough and eating to satisfy hunger, intense cravings for sweet or “junk” foods often subside anyway. Saullo also denounces this food rule, and clarifies a common myth by adding, “Sugars, added or naturally occurring, will be broken down and utilized the same way in the body.” As noted above, carbohydrates (i.e. sugars) are a preferred fuel source. Don’t fear, eliminate, or feel a need to intensely restrict sugars—or any other food group in the absence of a medical need to do so. Balance added sugars with natural (fruit, vegetable and whole grain) sugars.

In my work with runners and active clients, I try to instill a filter for food rules. If it seems regimented and restrictive, let it go! Eating a balanced diet, open to all food groups and food cravings, is more sustainable and will ultimately provide more nutrients. If you’re curious about your own diet quality, or want to work through some lingering food rules, consult a registered dietitian.