Glossary of terms

Weight-neutral: an intervention or service where weight change or weight control is not an intended outcome, and that trials have shown to have a negligible impact on body weight.

Weight-centric: an intervention, service or perspective where body weight change or body weight control is considered necessary or desirable.

Size Acceptance: unconditional acceptance of the past, current and future body weight and shape of yourself and others.

Size Diversity: Humans are a biologically diverse species, with great variation in factors including height, weight and body composition.  Even with the most health-supporting environment (timely medical care, no poverty, affordable & accessible nourishing foods, opportunities for physical activity etc) the population would still be physically diverse.

Size Inclusive: a service or intervention that caters for and welcomes people of all shapes and sizes.

Body Positive: a service, intervention or perspective where people of all body shapes, appearances, abilities, races (and other characteristics used to marginalise people) are considered unconditionally worthy of respect and care.

Weight bias: the medical preference for BMIs between 18.5 and 25, and assessment that a BMI over 25 is 'unhealthy'. In the same vein, both terms 'overweight' and 'obesity' are a direct result of weight bias because they are BMI based rather than being determined by an individual's pathophysiology.

Thin bias: the social preference for thinner bodies which is also related to western social constructs of beauty ideals and appearance standards. 

Anti-fat bias: Rejection of the appearance or perception of body fat (including on smaller bodies) and can extend to disdain for body composition fat percentage above a given number. A focus on becoming leaner alongside or instead of performance goals in sport is also an example of this kind of bias. 

Fat Stigma: the negative social consequences of thin bias. This can include being catcalled, romantically rejected, infantised, harassed, bullied, dehumanised and humiliated due to having a larger body size.  Fat stigma is most corrosive to someone's sense of self when it occurs in the family of origin.  If the larger-bodied person agrees with the negative beliefs attributed to their body they have developed internalised fat (or weight) stigma. Fat stigma is reinforced by negative portrayals of people with larger bodies in the news and entertainment media, for example the 'headless fatty' images that typically accompany news stories about 'obesity' and the ubiquitous fat-to-thin personal transformation narrative.   

Weight stigma: the negative interpersonal consequences of weight bias in medical and healthcare settings.  For example, a primary care provider (eg GP) who berates a client for their weight, dismisses their primary complaint to discuss their weight, advises weight loss for a condition that a smaller-bodied person would receive a different treatment for, assumes that someone with a larger body has a sedentary lifestyle or poor eating habits (without actually assessing either), assumes poor health literacy based on body weight etc. The consequences of weight stigma (understandably) include avoidance of healthcare services, diminished sense of self worth, shame, missed/delayed diagnosis of serious illness and exacerbation of mental health conditions such as depression and anxiety. Weight stigma also affects people outside of health and medical contexts, such as social settings e.g. family and friends, and community settings e.g. public transport, shops, gyms, schools, workplaces, which affect people's ability to participate in activities that benefit their health and well-being. 

Size Discrimination: when access to services or activities differs between larger and smaller bodied people. For example, if access to IVF services is arbitrarily limited due to BMI instead of functional testing, when access to adoption services are based on potential parents' BMIs, when joint replacement surgery based on BMI instead of strength and function tests.