Trail Runners Have A Dieting Problem (That Might Not Be Related To Weight)

Why dieting can lead endurance athletes down an unsustainable path, and what to do in the face of diet-related pressure.

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It’s January, and although most trail runners aren’t yet back to full training mode, diet season is just getting started. But…we’re trail runners! We don’t diet. We engage in “clean eating” and discuss macronutrient content. We talk about power-to-weight ratios and functional thresholds. We’re looking for a competitive edge, not trying to get back into our skinny jeans. This is just goal setting. “It’s a lifestyle change.” We’re “rewiring neural pathways,” or whatever the influencer with 5% body fat said on YouTube. Right? Right??

No matter how we want to talk about it, a diet is a diet. And while there’s no reason to condemn our desire to lose weight or change our bodies in the new year through dieting, it makes sense to ask some important questions about why we feel compelled to do so. So, let’s take an unflinching look at why we might start pulling out the calorie trackers (a bad idea, by the way) come January and attempt to discover if we’re struggling with our weight–or struggling with something much deeper.

First, some diet reality.

Though the Merriam-Webster dictionary defines a diet as a “regimen of eating and drinking sparingly to reduce one’s weight,” more modern interpretations of diets include following any specific plan of eating to alter body weight, body composition, health outcomes, or even engage with environmental, social, and economic concerns. For our purposes, we’re talking about any kind of eating plan that is begun with the hopes of effecting some kind of physical change—whether we tell ourselves it’s for aesthetics or improved physical function.

As you have likely heard, and as countless scientific studies will attest, diets do not work for many reasons. The following three are among the most relevant for athletes: First, as we take in less energy, our metabolism will slow down and make it harder for us to lose weight. Second, our body releases the hunger hormone ghrelin when we restrict caloric intake, making us ravenous in response to what the body perceives as famine. Third, cutting calories and/or carbohydrate intake will result in symptoms like fatigue, lethargy, and muscle pain that will likely make even light training feel awful.

Turns out, the body has some fail-safes in place for when we decide that we’d suddenly like to overcome our genetic set point—the range of weight at which our body likes to settle—and squeeze into smaller running shorts. When we eventually give up on the diet – because we feel terrible, can’t stop thinking about tacos, are a whole minute per mile slower, and haven’t pooped in a week – we’ll probably get angry with ourselves, frustrated over what we perceive to be an additional failure, and feel shame that we couldn’t hack it. This pattern of behavior is so common and so reproducible that it begs the question; in a community of highly intelligent people, why do runners keep trying to diet in January? The only logical answer is that maybe runners aren’t trying to diet at all.

The real reason you’re dieting (and it’s not a very good one)

The more we dive into research on weight loss, the more it seems like we’re using dieting to do a heck of a lot more than look good in tank-tops. Studies on the motivation to diet find that people often attach a huge amount of value to just the ability to restrict calories, whether or not they actually lose weight. That “skill” of restriction requires the dieter to have strong convictions about why they are regularly ignoring negative body signals and psychological distress, therefore it may bring about a sense of accomplishment when we’re able to stick to a diet. Research on mood in the first four weeks of a weight loss program shows that dieters gain an additional mood boost, even when their weight loss is minuscule. Perhaps the most powerful suggestion that dieting is a great idea comes from the pervasive and invasive diet culture message that we are inundated with from all directions, the main idea of which is simple–thinner and leaner is better, always.

We might think that we are impervious to these messages, but triathlete and coach Miranda Bush believes that even the endurance community is susceptible to diet culture and has written about body image issues in triathlon.

“The diet industry preys on the idea that you will be faster if you are thinner. We have to be very aware of marketing schemes that draw us into the belief that skinny is better at all costs,” Bush says. Research shows that these marketing messages have created an inextricable link between weight loss and success in our culture. Since the U.S. diet industry was worth a reported 78 billion dollars in 2019 before the pandemic hit, you can bet that there are a whole lot of stakeholders interested in keeping you hooked on the idea that your worth is tied to your weight.

We can’t deny the fact that there are aspects of dieting that can feel good–at least, for a while. Gretchen Mullin, a licensed mental health counselor, marathoner, and former competitive bodybuilder says that it’s hard to convince people that the sense of euphoria that they feel as the number on the scale goes down is likely not going to last.


“The diet industry preys on the idea that you will be faster if you are thinner. We have to be very aware of marketing schemes that draw us into the belief that skinny is better at all costs”


“Weight loss and management of body size or composition provides people with a sense of control and comfort,” Mullin says, explaining that diets give us the illusion that we can choose our body shape and size by modifying our eating and exercise habits, though this is largely determined by genetics. “This false sense of control helps us to manage stress and anxiety in the honeymoon phase of starting a diet. The more stressed we feel, the more we cling to this idea of being able to control what we look like–even if it’s not sustainable over time.”

Even the act of planning out what we’ll eat, prepping meals, and sticking to the plan can create a sense of calm and competence. Life may feel confusing, but at least we know we’ve got chicken breast packaged into perfect 6-ounce portions in the fridge–it’s powerful stuff. The problem comes when we either can’t or don’t want to continue the diet, and the feelings of shame and frustration that come along with quitting.

Body Image vs. Performance

Many of us may consider dieting in hopes to gain that elusive performance boost if we’re lighter, but it’s likely that body image concerns also play a role in our choice. In a study on 400 male and female runners, researchers found that runners had elevated levels of body dissatisfaction that correlated with eating disorder behaviors. We may think that women are more likely to struggle with body image, but Dr. Kyle Ganson, a researcher and professor at the University of Toronto, says that male athletes also feel a huge amount of pressure to adhere to the body type most associated with their sport. He says that men often look to the professionals and/or elites for inspiration, even when it’s not appropriate.

“These individuals portray success through their bodies and performance, both of which are usually out of reach for the vast majority of males, yet many aim to emulate them through their exercise and eating behaviors,” Ganson says.

Unfortunately, if we’re cutting calories “for performance,” we’re also cutting out valuable fuel that an athlete’s body needs to actually perform better. Although we’ll probably drop a few pounds initially, we’re likely losing muscle and with continued or rapid weight loss, we’re slowing down our metabolism too. Kirsten Screen, a registered dietitian who works with endurance athletes, says that improving performance is often about adding calories, not subtracting, and paying attention to micronutrients.

“Every process in the body is driven by micronutrients. If we don’t have enough of them or can’t assimilate them, everything suffers. Micros are doing the work behind the scenes– minerals, in particular, are driving the whole process,” Screen says an athlete with big goals needs to have enough fuel, plus the ability to break down, assimilate, and use nutrients to drive body processes.” This requires good gut health, which will likely be weakened when we go on a diet. Research on the effects of calorie and/or carbohydrate restriction in the gut shows that even short-term dieting can disrupt gut flora, making it more difficult to assimilate the smaller amount of food we’re taking in. This is not exactly an optimal situation for athletes who require not just fuel for training, but adequate nutrients to repair muscles and tissues in recovery.”

What to do if a diet still sounds like a good idea – any time of year.

Even if you agree that a diet is not a magic bullet or a cure-all, you might still decide to give it a shot. You may have compelling reasons and ultimately should do what you think is best. However, if you find yourself feeling pulled toward tightening things up, whether it’s January or July, it might be worth it to take a look through the following list of possible reasons before passing on the pasta. You just might find that you need to add something to your life, not subtract something from it.

The Situation: You just went through a major life event.

Any major upheaval in life is bound to make you feel a bit unmoored–and it’s not just the negative events like a death, divorce, illness, or trauma. Research on the effects of life events on health shows that stress is created by the amount of adaptation required to manage a life change. This means that even positive events like marriage, moving, or getting a new job can make you feel a bit frazzled. Any time we experience something that dials up the fear and dials down the confidence, many of us may turn to dieting as a way to pump the brakes and get control over chaos.

The non-diet fix: 

Be patient and give yourself some time to settle into your new life. Recognize that even if you do lose weight, your anxiety will likely still be there, so consider working with a mental healthcare practitioner to process those uncomfortable emotions. Refocus on what’s stable and what you can build on for the future. Set an athletic goal that’s not weight-related to feel accomplished without the pressure.

The Situation: You don’t like what you see in the mirror.

If we’re being honest, there are plenty of reasons to become dissatisfied with your appearance. Weight fluctuations, aging, body image pressures, comparison to elites, and even too much time on social media can all mess with your perceptions. Plus, as Miranda Bush notes, “It certainly doesn’t help that everyone is wearing very tight, figure-exposing spandex in our sport.” It’s important to think beyond the reflection. Not liking how we look is usually code for, “I’m afraid of what people think of me.”

The non-diet fix:

Don’t let diet culture tell you that success is tied to your physical appearance. Our work is to unravel those complex emotions and begin to detach ourselves from focusing on other people’s judgments. Bush has more great advice: “When an athlete comes into the sport, I always suggest that they explore and define their values, and understand why the choice to participate in endurance athletics honors the core of who they are. When it comes to their physical body, I urge them to focus on what their body can do, rather than how this will change their body composition.”

The Situation: You want to improve performance.

This is tricky. For some of us, improving athletic ability is a question of personal satisfaction. For others, it’s a way to compensate for a lack of self-esteem. Be honest with yourself about which it is and recognize that getting smaller might be counterproductive. When a client has a goal of improving athletic performance, weight loss is not even on Kirsten Screen’s radar. Instead, she dives into assessing things like gut flora, stomach acid, genetic links to nutrient assimilation, food quality, and lifestyle habits in order to help the person achieve their goals.

The non-diet fix:

If you want to build a fast machine, the last thing to do is deprive it of fuel. Hire a registered dietitian (you can find one here), preferably with a non-diet approach, to improve your fuel intake and optimize nutrient assimilation. Consider hiring a coach to be sure that your training plan matches your goals. Sleep and be sure to take rest days! Many athletes mistake lagging performance for a lack of adequate rest and recovery.

The Situation: You’ve had recent and specific weight gain.

There are occasions when a specific catalyst will cause you to gain weight. Medications, illness, and injury can alter your habits, hunger, and the way your body uses energy. Even a change in routine, like driving instead of walking to work, can mean the addition of a few pounds. It makes sense to want to regain fitness, but beware of trying to do so as quickly as possible or risk diet burnout, possibly trigger binge-like behavior, and likely struggle to amp up performance in your underfueled state.

The non-diet fix: 

Check in with yourself–are you trying to “get back to normal” or trying to erase insecurity over your current body shape/size and athletic ability? The answer might determine how successful you are at building back to a sustainable routine. As activity ramps back up or you wean off medication, be sure to eat normally to fuel your training, and resist the temptation to additionally restrict calories. And again–be patient.

The Situation: It’s that time of year.

Unbelievably, many companies hold an “Office Weight Loss Challenge” (OWLC) every January where employees are encouraged to compete at dropping pounds. It’s hard to avoid that peer pressure since not only is everyone in the office on a diet, everyone is talking about being on a diet. Other folks like to mark the new year with a fresh start and might gravitate toward detoxes, cleanses, juicing, and other diet plans that claim to reset the body in some way.

The non-diet fix:

In a 2015 study on OWLCs, researchers list the myriad reasons why they’re a terrible idea and discuss the damaging effects. No matter the perks, the prizes, or the peer pressure, you don’t need to participate in competitive weight loss. If you’re looking for a fresh start, consider focusing on an activity that contributes positively to your athletic life, like finally figuring out bilateral breathing or mastering quick bike tire changes.

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