Calming Your Nervous System Can Work Wonders on Digestive Issues and Anxiety, According to RDs. Here’s How

What do I mean by that, exactly? Maybe these questions I ask my clients might illuminate things for you. Do you find it hard to slow down enough to eat lunch? Or have issues identifying what sounds good to eat for dinner? Perhaps you only want highly palatable foods (high fat, high sugar), you have rigid food rules or obsessive food thoughts, or find it difficult to stop eating past your body’s fullness cues.

These are all signs that a person is struggling to sustain an adequate, balanced, and enjoyable eating pattern—meaning that they’re not eating enough food (or a wide enough variety) to maintain their energy and emotional needs. And chances are high that your nervous system is contributing to the problem.

As a dietitian who works with people struggling with disordered eating and eating disorders, understanding and integrating nervous system regulation—aka ways to support and manage how you respond to stresses and stimuli—into my work with clients has been a significant game-changer. With an awareness of what is happening in your own nervous system, you can understand why and how your dysregulation is leading to food struggles, develop and implement tools to regulate your system, and experience a more peaceful relationship to food.

How your nervous system impacts your mental health (and vice versa)

In order to understand how the nervous system can impact your relationship with food, we have to first understand what the nervous system even is. Specifically, I’m referring to the autonomic nervous system, which regulates involuntary bodily processes like heart rate, blood pressure, and digestion. (Basically, it works in the background on the stuff that keeps you alive without you having to think about it.)

“Big picture, our nervous system impacts our perceptions of safety and threat,” explains dietitian Allie McKinney, RD. “Our nervous system states can impact whether we feel safe, calm, and connected to others; anxious or hypervigilant; or dissociated or apathetic.” According to Polyvagal Theory, a concept developed by psychologist and neuroscientist Stephen Porges, those three responses are governed by different parts of the autonomic nervous system: the sympathetic nervous system (SNS) and either the dorsal vagal or ventral vagal pathways of your parasympathetic nervous system (PNS).

“The SNS prepares our body for intense activity when we are stressed or in danger,” explains Amanda Marks, LPC, of Resilient Counseling. The SNS triggers hyperarousal, when you are super responsive and revved up. (You likely have heard this referred to as the fight-or-flight response.) Typical signs of hyperarousal include increased heart rate and blood pressure, clammy hands and feet, flushed skin, increased tension, trembling, heightened senses, aggression, and agitation.

Meanwhile, you can experience hypoarousal, or feel immobilized or frozen, when the dorsal vagal pathway of your PNS is activated. Symptoms of hypoarousal include disassociation, feelings of numbness, flatness, exhaustion, social withdrawal, or memory loss.

Both hyper- and hypoarousal are nervous system responses in times of threat (or perceived threat) to seek safety. But there is a third state of equilibrium, ruled by the ventral vagal pathway of the PNS. Experts also refer to this as the window of tolerance—when we feel safe, connected, stable, and present, and are best able to manage emotions and function well.

“For example, when we are connected to others and ourselves and able to regulate our feelings and emotions, then we are functioning optimally and our nervous system is also functioning optimally,” Marks says. In this state, our breath and heart rate are stable, and our digestive systems are working well. “It helps us to decide if a perceived threat is dangerous or not and gives us time to respond to any cues of danger.”

That window of tolerance is important for helping you deal with everyday stressors or problems. And some people can handle more and still stay in that window of tolerance than others. “If a nervous system is chronically stressed or has been chronically stressed, our window of tolerance is smaller and threats of danger may be magnified or overwhelming to us,” says Marks. “For example, if we are chronically stressed or hyperaroused, our SNS keeps us in a fight-or-flight state when we don't need to be,” she says. This might result in an increased heart rate, rapid and shallow breathing, and a dysfunctional digestive system.

On the other hand, Marks says we can come hypoaroused as a result of continued stress and overwhelm, or “being so aroused that we just start to shut down and check out, and we become disconnected from our conscious awareness.”

Generally, when we are not regulated (so, not operating in that window of tolerance) our nervous system wants to protect us. But when we are regulated, we are in connection with ourselves and the world around us. “The goal here is not to be calm all the time, but to be regulated enough so that when stressors come to us, we are able to respond to these stressors [appropriately],” Marks says. Your body would be able to differentiate between an actual threat (like a rampaging tiger lunging toward you) versus something like going to Trader Joe’s on a Sunday afternoon (stressful, but manageable and not life-threatening).

How the nervous system impacts your relationship with food

When we are constantly hypo- or hyperaroused and not living in our windows of tolerance, our nutritional status and relationships to food can be significantly compromised. “From an evolutionary perspective, it’s not especially advantageous to be eating or spending energy on digestion when we need to be on the lookout for bears,” McKinney says, describing hyperarousal. “When we feel anxious and hypervigilant, our eating may be rigid, perfectionistic, or obsessive.” My clients who are hyperaroused also experience symptoms like bingeing, eating past fullness, stomach upset, and restriction.

“From an evolutionary perspective, it’s not especially advantageous to be eating or spending energy on digestion when we need to be on the lookout for bears. When we feel anxious and hypervigilant, our eating may be rigid, perfectionistic, or obsessive.” —Allie McKinney, RD.

Meanwhile, “if we’re feeling dissociated [or hypoaroused], we may use food just to feel something, or avoid eating all together,” McKinney explains. I also observe hypoaroused clients (which typically comes with a low mood, or feeling numb or checked out) wanting only high-fat and high-sugar foods to feel something, checking out at meals because they’re overwhelmed, and having a hard time making food decisions because they feel disconnected from themselves. Both hypo- and hyperarousal can cause gastrointestinal distress.

Sometimes, especially when dealing with an eating disorder or disordered eating, food can be coupled with hard emotions and trauma and feel like a real threat. In such cases, resorting to behaviors like restriction or bingeing feel like safety—kind of like a faux window of tolerance. “Mentally, our threat responses bypass our ‘logic brain,’ meaning it’s hard to think your way out of them,” McKinney adds. “So many of my clients ‘know’ their beliefs around food aren’t objectively true, but that doesn’t make them ‘feel’ true, and their nervous system still perceives food as the threat.”

“For clients with eating disorders, their interoception is weakened,” adds dietitian Rebecca Jaspan, MPH, RD, CEDS, CDCES, referring to the ability to understand how or what you’re feeling (including hunger or fullness) at a given moment. People with eating disorders might also misinterpret signals like hunger and fullness as threats, she says. “Recognizing these signals and using tools to engage the parasympathetic nervous helps them change how their brain perceives food and ultimately results in them being able to nourish themselves more adequately over time.”

McKinney points out that being dysregulated often makes executive functioning tasks critical to eating—like planning and prepping meals or grocery shopping—challenging. “When we are dysregulated, our bodies are in pure survival mode,” Marks agrees. “Our bodies think we are about to die or be badly harmed, and going to the store is last on the list of things we need to do to survive…Our bodies just want us to escape the situation and perceived threat.”

Yet when we are well regulated in that window of tolerance, we can more easily manage such everyday tasks. “When we are in a calm and connected place, it allows us to stay present, be aware of what we and our bodies need, actually enjoy our food, and have compassion for our choices, even when imperfect,” McKinney says.

“When we are in a calm and connected place, it allows us to stay present, be aware of what we and our bodies need, actually enjoy our food, and have compassion for our choices, even when imperfect."

In my practice, I notice clients in their windows of tolerance are better able to access their “wise mind,” or their truest selves, and act in accordance with their values. It’s easier for them to eat enough, digest well, positively affirm themselves, self-soothe, and use mealtime tools we developed together.

To clarify, living more often in our windows of tolerance doesn’t mean we don’t experience stress. But it does mean we are better able to handle that stress (and recover from it) in health-supportive ways. “Being able to respond well to stressors in life is a skill that affects all our body systems,” explains dietitian Stephanie Darby, RD. “It is supportive to digestion, the gut microbiome, blood sugar and insulin levels, as well as energy and metabolism.”

Ways to befriend your nervous system during and outside of mealtimes

The main objective of nervous system work is to seek and find safety. “Safety is knowing and feeling safe in our bodies and mind,” Marks says. “Feeling safe is very important because we can logically know that we are safe, but if we don't feel safe, that SNS will take over and further make us feel unsafe.” When it comes to food, tending to your nervous system can help you nourish your body sufficiently and pleasurably, and develop a more harmonious and trusting relationship with food and your body.

Understanding how your nervous system works can help soften your lens on your relationship to food. “Sometimes it really helps people to have some compassion for themselves when they can understand what’s going on in their bodies and why things feel so hard,” McKinney says.

Knowing how to regulate your system around mealtimes and throughout the day can be empowering. Here are some ways to tend to your nervous system:

1. Get to know your system

Before trying tools, take some time to consider what it feels like to be hyperaroused, hypoaroused, and regulated. “It is very important to understand your actions and feelings when in these various states,” says Marks, “and working with a licensed therapist can help you identify opportunities and threats that need to be explored and processed.” For example, a therapist can help you unpack what you typically feel when you’re super stressed and how you typically try to cope—and offer strategies and insights to help you find more effective or healthier coping skills.

“Utilizing tools such as yoga, meditation, and other healthy coping skills expand our window of tolerance and contribute to being in a regulated state—we are thriving in this state, as opposed to being in survival mode,” Marks adds.

One of my favorite books to support nervous system exploration is Anchored: How to Befriend Your Nervous System Through Polyvagal Theory by Deb Dana.

“Utilizing tools such as yoga, meditation, and other healthy coping skills expand our window of tolerance and contribute to being in a regulated state—we are thriving in this state, as opposed to being in survival mode.”

2. Check in regularly

Take a few minutes to check in with yourself throughout the day—and before, during, and after mealtimes—to see where you are in your nervous system. “As clients gain an awareness of what’s happening in their systems and a better sense of what they might need in these situations, we can start to use toolsas ongoing ‘maintenance’ regulation,” McKinney says. “It’s much easier to make sound decisions about how we fuel ourselves from a place of safety.”

Not sure what a check-in would look like? Start with a simple grounding exercise of placing your feet firmly on the ground and bringing awareness to your breath. Then, ask yourself, “Am I regulated, hyper-, or hypoaroused? What do I need to get more regulated if not already?” It can be as simple as that.

3. Increase safety cues

According to Polyvagal Theory, our bodies have an unconscious surveillance system, termed neuroception, that is always assessing safety and risk around us. By integrating calming and soothing elements into mealtimes (and elsewhere), we can help ourselves to sense safety in situations that might normally be stressful. This could look like wearing a weighted blanket on your lap while you eat, displaying objects evoking a safe memory (like shells from a beach trip or a pinecone from a nature walk) on the dinner table, or looking at photos of loved ones during a meal.

4. Lean on co-regulation

Being in safe relationships is another way to enhance nervous system regulation. Reach out to your safe person or safe people (pets, too!) and allow them to be a part of your nervous system work. Ask your partner for a hug when you're feeling super stressed to help you come down, or ask them for help talking out or labeling your feelings.

5. Practice mindfulness

When you’re hyperaroused, it can help to practice breathing with an emphasis on the exhale. You can breathe in for 3-4 counts and out for 7-8 counts and repeat for several rounds. When you’re hypoaroused, it can help to practice upregulating breathing practices, such as breath of joy, and gentle yoga practices or other forms of mindful movement.

Other techniques, like meditations and body scans, can be soothing when hyperaroused and support embodiment and interoception.

6. Try grounding practices

When you are hyperaroused, grounding practices can help you come down. Examples are spending time in nature, “nesting” or building a pillow fort, putting bare feet in grass or sand, or simply feeling your feet, seat, and back connection the chair and floor.

7. Use cold water

Ever wonder why people love cold showers or taking polar plunges? Cold water stimulates the vagus nerve, supporting physical, emotional, and mental regulation. Try an ice pack or cold water on your face if you don’t love the idea of cold showers or swimming in freezing waters (like me).

8. Engage your senses

When you are hypoaroused, using sense engagement can help you come up. Examples are engaging sense of smell through essential oils or sense of touch through petting your dog. Engage any or all your five senses and see what feels regulating.

9. Incorporate music

Putting on soothing music around mealtimes when you’re hyperaroused can support down-regulation. On the other hand, listening to uplifting and energizing music (and dancing, too!) can help when you’re hypoaroused and support up-regulation.

10. Find "glimmers"

According to Polyvagal expert Deb Dana, glimmers are micro-moments when we feel a spark of regulating energy, which can help build foundations of safety and regulation. Glimmers are moments we must intentionally seek out or they will be missed. Examples are watching a bird outside your window, taking in the scent of fresh flowers on a walk, or watching a sunset or sunrise. “The smell of the ocean air or fresh cut grass help me feel more regulated and at peace when I'm feeling upset or anxious,” Marks shares. Those are her "glimmers," she says.

“The smell of the ocean air or fresh cut grass help me feel more regulated and at peace when I'm feeling upset or anxious,” Marks shares. Those are her "glimmers."

Take your time getting to know your system and which tools work and don’t work for you. “No two people are going to respond the same, but overall, the theme is to find what helps you feel ‘safe enough,’" McKinney explains. “Once you find something that feels worth a try, practice it often to allow your nervous system to learn. It’s much easier to access regulation in a challenging moment when we have lots of practice using these tools from a place of relative safety.”