what is psychological flexibility and why does it matter in nutritional therapy (even if you don’t work in disordered eating)?
As nutritional therapists, we often focus on the what and how of nutrition: what to eat, when to eat, and how to meet health goals, etc. But underneath every food choice is something deeper. I’m referring to a client’s inner world, including their thoughts, emotions, and physical sensations (such as cravings and urges). Clients aren’t just following a nutritional health plan; they’re navigating a complex internal world.
That’s where psychological flexibility comes in.
Even if you don’t work with disordered eating, understanding this concept can greatly improve client outcomes. It’s a core psychological skill that supports behaviour change, resilience, and sustainable behaviour change. And I believe that it should be part of every nutritional therapist’s toolkit.
what is psychological flexibility?
Psychological flexibility is the ability to stay open, aware, and engaged in actions that align with one’s values, even when it’s hard.
It means being able to:
Notice difficult or intense thoughts or emotions without acting on them
Stay connected to the present moment (rather than getting caught in past failures or future fears)
Make choices based on what really matters, rather than what feels safe, familiar, or comfortable
This concept comes from Acceptance and Commitment Therapy (ACT), a psychological approach used in a wide range of health contexts, from chronic pain and diabetes to anxiety, weight management, and beyond.
Psychological flexibility helps people do what works, not just what feels good or more comfortable in the moment.
why its relevant in nutritional therapy
No matter what kind of clients you support, whether it’s digestive health, metabolic conditions, fertility, sports and performance or hormonal balance, behaviour change is at the heart of your work. And where there’s behaviour change, there’s discomfort.
Here are some common examples we might see in our nutritional clinics:
A client wants to reduce emotional eating, but snacks after dinner to relax
A busy parent struggles to prioritise regular meals, even though they know it would help their energy
A client struggles to eat ‘according to plan’ despite it worsening their digestive symptoms
A client wants to change but feels overwhelmed and stuck in their old patterns
All of these examples involve some level of psychological inflexibility; rigid thinking, avoidance, or an inability to stay present and respond with intention and meaning.
And one thing I’m sure of, psychological inflexibility is what can keep clients stuck.
how psychological flexibility can help your clients
Psychological flexibility helps clients:
Tolerate discomfort (e.g. hunger, cravings, guilt) without acting on it
Loosen the grip of unhelpful thoughts, like “I’ve ruined everything” after a relapse
Stop avoiding change, even when it feels scary or unfamiliar
Reconnect with values, such as energy, parenting, or vitality, to guide their choices
Build long-term habits, not just short-term fixes
It turns “I’ll never get this right” into “This is uncomfortable, but I can still move forward.”
what this looks like in practice
As a nutritional therapist, you can support psychological flexibility by:
Normalising discomfort: “It’s understandable to feel anxious when trying something new.”
Helping clients notice their thoughts, rather than getting stuck in them: “What’s your mind telling you right now?”
Using values-based questions: “What kind of life do you want your nutrition choices to support?”
Encouraging small, flexible experiments, rather than rigid, all-or-nothing plans
Modelling curiosity and compassion, rather than judgement
This isn’t therapy. It’s psychological awareness, and it makes you more effective at supporting clients to change.
final thoughts
Whether you’re supporting clients through complex gut protocols or helping them improve their everyday energy, psychological flexibility is what allows them to follow through, even when life gets hard (which it of course it does!).
Understanding this skill will help you:
Navigate resistance with empathy
Empower clients to work with (not push against) their inner experience
Create nutritional plans that are resilient and flexible, rather than rigid
Promote meaningful, lasting change
If you’d like to go deeper into these kinds of psychological tools for clinical nutrition practice, the Nutritional Therapy for Eating Disorders: Advanced Practitioner Programme includes training in psychological flexibility and behaviour change strategies for all practitioners working with food and wellbeing. Join the priority waiting list here.