A Somatic Look at Eating Disorders and the Nervous System
The concept of a pervasive drive for autonomy, or PDA, describes a fundamental, hardwired need for personal agency and freedom from coercive control. This is not merely a preference but a core biological imperative linked to our survival. Our nervous system is constantly scanning the environment, asking one primary question: "Am I safe?" Safety is not just the absence of physical threat. It is equally comprised of psychological safety, which includes the freedom to make choices, to have a voice, and to feel a sense of control over one's own body and life. When this autonomy is persistently threatened or undermined, the nervous system perceives profound danger. It must then adapt, finding creative and often costly ways to establish a sense of safety and control where the external world fails to provide it.
From the lens of Polyvagal Theory developed by Dr. Stephen Porges, we can map these adaptations with greater clarity. This theory outlines a hierarchical nervous system where our physiological state dictates our psychological and behavioral experience. The ventral vagal state represents safety, social connection, and flexibility. When we feel safe and autonomous, we reside here. However, when demands, whether explicit or implicit, feel overwhelming and coercive, they can trigger a shift into a sympathetic fight or flight state, or even into a dorsal vagal shutdown state. For an individual with a high pervasive drive for autonomy, external demands are not simply inconveniences. They are neurological triggers, interpreted by the system as threats to personal integrity that must be defended against at all costs. The nervous system, in its survival oriented logic will seek any available lever to pull to regain a foothold of control.
This is where the behaviors commonly labeled as eating disorders can be reframed. They are not merely about food or body image, though those are the arenas in which the battle is fought. They can be sophisticated, albeit destructive, nervous system survival strategies. When a person feels their autonomy is chronically under assault, perhaps from a high pressure family, a rigid cultural ideal, a traumatic history, or any environment that feels controlling, the body seeks a domain where it can be the ultimate authority. Food intake, body size, and rituals around eating become one of the few realms of unquestionable control. Restriction can be a powerful expression of this. The act of saying "no" to food, of mastering hunger, can create a potent sense of agency and superiority, a sympathetic nervous system fueled fight response against the perceived demands of the world, including the demand to eat. It is a way of asserting, "You cannot make me do anything. I am in control here."
Conversely, bingeing can serve a similar, if opposite, regulatory function. In a state of sympathetic overwhelm or dorsal vagal collapse, a binge can be an attempt to self soothe, to numb out, or to fill an emotional void. It is a frantic, often dissociative, act of taking in, of attempting to regulate a dysregulated system through the intense sensory experience of food. The subsequent purge can then be understood as a violent expulsion of not just the food, but of the feelings, the demands, and the perceived toxins of the external world. It is a cycle of taking control and then purging the evidence of a loss of control, a desperate pendulum swing as the nervous system seeks equilibrium. Avoidance of food related social situations is another clear behavioral output, a flight response from demands and potential judgment. Through this polyvagal informed perspective, we see that the individual is not broken. They are adapted. Their system has found a way, the only way it knows, to protect itself and to scream for the autonomy it so desperately needs to feel safe and alive. The path to healing, therefore, must involve creating genuine experiences of safety and collaborative choice, helping the nervous system relearn that agency can exist without self destruction, and that true safety is found in connection, not in isolation.
