Eating disorders, Research

'I feel full with shame': Gastric interoceptive sensibility and its relationship to body image

Lucy Stafford reflects on her research on how hunger, fullness, and satiation is physically and emotionally experienced and what this means for how we feel about our body.

28 February 2024

Importance

The House of Commons Health and Social Care Committee (2022) has named body image (how we perceive, think, and feel about our bodily appearance) a clear determinant of the physical and mental health of UK citizens. Indeed, their report outlined the link between body image, eating disorders, depression, and anxiety. The importance of body image to our physical and mental wellbeing makes it important to explore the factors that contribute to it.

Research has started to link interoceptive sensibility, the process by which we consciously interpret sensations that arise within the body to communicate its condition (Khalsa et al., 2018), to body image. Interoceptive sensibility in the gastric system in particular (i.e. our interpretation of sensations from our stomach) has an intuitive link to body image: What and how much we eat can change our bodily appearance, and this might influence body (dis)satisfaction (Preston & Ehrsson, 2014).

Rationale

Although research has begun to quantify the association between gastric interoceptive sensibility and body image, research prior to this project had no clear conceptualisation of what gastric interoceptive sensibility is. This is because current questionnaires have not been developed through focus groups or interviews where target populations can discuss their understanding of gastric interoception. Without listening to first-hand accounts, how can we expect the current measures to be comprehensively capturing gastric interoception?

This inspired the first research aim of my Masters project: To explore how gastric interoceptive sensibility is experienced. The absence of a complete conceptualisation of gastric interoceptive sensibility also arguably leaves us with a limited understanding of its relationship to body image. This is problematic, given the significance of body image to our physical and mental health. This led to my second research aim: To explore how body image is experienced in relation to gastric interoceptive sensibility.

Methods

Both aims were addressed by conducting 12 online semi-structured focus groups with 78 participants who identified as having a gastric disorder, eating disorder, or no eating or gastric disorder. We wanted to include participants with an eating and gastric disorder in particular so we captured the diverse nature of gastric interoception.

To validate the use of self-diagnosing eating disorder and gastric disorder samples, we also asked these participants to complete disorder-relevant questionnaires. During the focus groups, participants were asked to describe the gastric/bodily sensations and emotions they experience when full (i.e. 'stuffed'), satiated (i.e. an absence of hunger or fullness after eating, eating until a point of contentment), and hungry.

They were also asked to discuss the impact of these sensations and emotions on how they thought and felt about their body. Transcripts from the focus groups then underwent hybrid inductive and deductive thematic analysis.

Findings

How is gastric interoceptive sensibility experienced?

Our findings were rich and insightful. Participants experienced gastric interoceptive sensibility as the physical sensations and emotions felt when describing themselves as full, satiated, and hungry.

Fullness was reported as having physical repercussions on how the stomach and body felt. Participants experienced fullness as pain, nausea, stomach tension, heaviness, being at capacity, feeling sluggish, and feeling immobile. Fullness also inspired a variety of responses, with participants engaging in rest, exercise, distraction, increasing water intake, and planning to avoid fullness on the next eating occasion. The physical experiences could also be dependent on the food eaten. Fullness was also reported as having emotional repercussions. Fullness made participants feel worried about impacts on bodily appearance and function, out of control, guilty, regretful, and disgusted. Interestingly, some participants described a sense of contentment, completeness, and pride when experiencing fullness. Others described a sense of emotional neutrality, or that the emotions experienced depended on the context of the eating experience (e.g. in isolation versus in a social setting).

The physical and emotional effects of satiation varied dramatically between individuals. Some reported that their body felt energised, whilst others said their stomach felt tense. Others reported an absence of bodily or gastric sensations during satiation. Participants said the physical sensations experienced when satiated could be dependent on the food or portion size eaten. Satiation was associated with positive emotions such as contentment, peace, and hope. In contrast, it could make others feel unfulfilled and worried about delayed discomfort. Others described satiation in terms of emotional neutrality, or their emotions being dependent on whether recent previous eating experiences had been experienced as painful.

Hunger was characterised using bodily and gastric cues, including discomfort, stomach rumbling, stomach movements, emptiness, nausea, tiredness, light-headedness, detachedness, and headaches. Hunger was also described in terms of how it was responded to. Hunger could be ignored, refused, disbelieved, responded to with water, and by eating. Hunger was also associated with negative emotional cues, such as anger, sadness, and worry.

How is body image experienced in relation to gastric interoceptive sensibility?

Participants also experienced their body image differently depending on their physical and emotional experience of fullness, satiation, and hunger. Fullness was found to promote a negative body image, with participants feeling as if their body had grown larger and feeling dissatisfied with this. Participants described feeling 'fat' due to bloating and disgusted with their body. Participants also said that fullness could make them feel as if their body was dysfunctional, as it limited what they could then do with their body, for example, if they were able to exercise.

Satiation could make participants feel positive about their body, particularly in terms of how it was now 'fuelled' to carry them through the rest of their day. Other participants described feeling neutral towards their body due to the lack of physical sensations and emotions that accompanied the state of satiation (compared to fullness or hunger). Satiation could also promote a sense of control over bodily appearance and their physiological condition. For some participants, satiation could also lead to a negative body image because they still worried about the impact on their size and health.

Finally, hunger could distract people from thoughts about their body, as their priority was to eat. Instead, they thought of their body after eating. Participants also expressed appreciation of their body's ability to communicate its needs, allowing them to take pride in its functionality. Hunger could also promote restriction, with some participants feeling triumphant when they had reached the level of hunger that resulted in physical cues because it meant that their body was getting smaller.

Implications

The massive diversity in how gastric interoceptive sensibility was experienced by our participants reinforced our concerns that current measures are not capturing it as comprehensively as they could be. The physical and emotional nature of gastric interoceptive sensibility also highlighted to us the importance of bodily experience to emotional experience.

The explicit links participants made between gastric interoception and body image strengthens the published quantitative relationship, but makes it clear that this relationship is more complex and nuanced than initially uncovered: How participants thought and felt about their body depended on if they were experiencing the physical sensations and emotions accompanying fullness, satiation, or hunger.

To conclude our research, we believe gastric interoceptive sensibility can be conceptualised as the physical sensations and emotions that arise from or due to the gastric when full, satiated, or hungry. Further, the meanings we give to gastric sensations (i.e. bloating means I am full and fullness means my body will get bigger) are differentially related to our body image. Interventions that aim to promote body satisfaction may focus on reappraising the meanings we assign to gastric sensations and their associated emotions.

Future plans

The next stage of our project includes conducting in-person focus groups to improve the trustworthiness of this online data and asking participants to explicitly define what fullness, satiation, and hunger are. We then hope to use this data to develop and validate a novel gastric interoceptive sensibility scale in accordance with best practice for use in research and clinical settings. I am particularly excited about potential applications of this research for eating disorder patients, a population with dysfunctional gastric interoception and poor body image.

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Author biography

Lucy Stafford is a first-year PhD student at the University of York. She conducted this research under the supervision of Dr Alex Pike and Dr Catherine Preston during her Masters in Social Research, which she undertook as part of her 1+3 PhD funding from the Economic and Social Research Council. Her PhD research will continue to build on the interaction between the internal body and external body. Outside of her PhD research, she is also interested in the perinatal bodily experience, body representation and cognition in eating disorders, and online data integrity.

Twitter/X & Bluesky @LucySta02475610.