Some definitions have been adopted from reputable sources in their entirety due to their widespread acceptance or appropriateness; others have been adjusted or newly developed based on ongoing engagement with The WELL Collaborative members, partners, and other stakeholders we engage with through the course of our diverse work. These definitions will be reviewed and may be adjusted over time as we learn and discover more about this complex space.

Term	Definition
Bariatric surgery	Bariatric surgery includes different operations on the stomach and digestive system which result in weight loss by reducing food intake and absorption of calories while altering the body’s handling of energy and its appetite.1
Body mass index (BMI)	A simple index of weight-for-height that is commonly used to classify weight categories in adults. It is defined as a person’s weight in kilograms divided by the square of a person’s height in meters (kg/m2).2 BMI measurement cut offs for classification and diagnosis of potentially unhealthy weights are the same for both sexes but do have variations for some ethnic groups (including Aboriginal and Torres Strait Islander peoples), older adults, muscular individuals or highly trained athletes, and pregnant women.3 BMI is an effective tool for monitoring population level trends in weight. It can also be used to identify a person’s risk of developing health conditions such as obesity and some chronic diseases. However, it cannot be used as a diagnositic tool when used alone. BMI is a measure of size – not of health.4 BMI calculations used for adults cannot be applied to children. In children BMI z-score or BMI centile should be used.5,6
Burden of disease	“The burden of disease is a measurement of the gap between a population’s current health and the optimal state where all people attain full life expectancy without suffering major ill-health.”7
Discretionary foods	Foods and drinks not necessary to provide the nutrients the body needs, but may add variety and enjoyment to eating. Discretionary foods contribute an excess amount of energy (kilojoules or calories) and are high in saturated fat, sugar, salt and/or alcohol. They can be included sometimes in small amounts, and by those who are more physically active or with increased energy needs, but are not a necessary part of the diet.8
Disordered eating	“Disordered eating is present when an individual engages in abnormal eating patterns or food behaviors on a regular basis. This does not generally apply to those with specific food intolerances or health problems, who might have no choice but to adhere to a certain diet.”9 People with eating disorders exhibit disordered eating, but not all people with disordered eating can be diagnosed with an eating disorder. The difference lies in the frequency and severity of behaviors and the distress they cause to the person. See also: Eating disorder.
Early intervention	Provision of support or interventions to a person or family at-risk of becoming overweight (at the upper end of the healthy weight range) to prevent or limit a foreseeable decline in their health.10
Eating disorder	An eating disorder is a diagnosed type of disordered eating.11 Eating disorders can only be diagnosed by an appropriately trained medical professional according to specific diagnostic criteria. People with eating disorders exhibit disordered eating, but not all people with disordered eating can be diagnosed with an eating disorder. The difference lies in the frequency and severity of behaviors and the distress they cause to the person. See also: Disordered eating
Edmonton Obesity Staging System (EOSS)	A risk-stratification system for adults that uses five graded categories, based on a person’s morbidity and health risk profile.12 Factors such as BMI are measured alongside metabolic, mental health, and physiological factors to determine a more complete risk profile, diagnosis of obesity, and management plan. The EOSS is only applicable to adults, however, an adjusted paediatric version is currently being investigated that captures the severity of disease in children, as well as factors that complicate management, within four domains of health most commonly encountered in obesity: metabolic, mechanical, mental health and social environment.13
Family-centred care	“The delivery of health care based on partnerships between patients, families and all those involved in the care of the child and family.”14 See also: Person-centred care
Health	“Health is a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity.”15
Lifestyle modification	Changing personal behaviours or habits associated with how we live our day-to-day lives that can impact our health and wellbeing, and maintaining these changes in the long-term. Areas that are often addressed in lifestyle modification programs or policies include diet, physical activity, alcohol intake, and smoking (these areas are the risk factors that contribute most to the burden of disease in WA).16 Other areas may also be included within the definition of lifestyle modification such as wellbeing, self-care, sleep, social interactions etc.
Metabolic Syndrome	Metabolic syndrome is a group of five conditions that together can lead to heart disease, type 2 diabetes, stroke and other health conditions. Metabolic syndrome is diagnosed when someone has three or more of the following risk factors: high blood glucose (sugar), low levels of HDL (good cholesterol), high levels of triglycerides (fats within the bloodstream), large waist circumference, or high blood pressure. Metabolic syndrome is only applicable to adults.17
Nutritious eating	Eating a variety of foods from each of the five food groups daily, in the recommended amounts for a person’s age, sex, and medically advised nutritional needs, and limiting the intake of discretionary foods.18
Obesity	Obesity is a chronic relapsing condition characterised by high amounts of body fat. It can be measured using BMI, waist measurements or a more direct measure of body fat stores. High levels of body fat (particularly around the organs) can affect a person’s health, and increase the risk of certain diseases (including type 2 diabetes, heart disease and certain cancers). How a person’s body stores fat, and the effect it has on health, is highly individual. Not everyone in a larger body is unhealthy, and not everyone in a smaller body is healthy. Genetics, hormones, medications, and other environmental factors influence the likelihood a person will develop obesity.
Obesogenic environment	Obesogenic environment Used to describe an environment that promotes unhealthy habits, such as frequently eating discretionary foods and low levels of physical activity, which can contribute to obesity and represents the influencing factors that are largely outside of a person’s control to change. Schools, workplaces, homes and neighbourhoods, the media, availability of convenience foods, and portion sizes can all influence a person’s body weight.19
Person-centred care	“Refers to the whole person, going beyond the narrow focus of their symptoms and treatment, and applies a holistic approach to care that acknowledges the wider social, psychological, societal and cultural factors that may affect the individual and their healthcare journey. This includes incorporating a person’s family and/or carer in decision making to the extent the individual chooses.”20 See also: Family centred care
Person-first language	Person-first language puts the person before the condition, thus removing the condition from being a part of an individuals identity and instead considers it as something the individual lives with.21 This framing is how we endeavour to talk about all health conditions in the first instance and in public communications. However, at an individual level, some people may choose to adopt language that places their condition as part of their identity. Everyone gets to make this choice for themselves and health care professionals can support people by using the language that the person chooses and feels most comfortable with.
Person living in a larger body	A person who has elevated levels of fat deposits but might or might not be medically diagnosed with obesity. ‘Living in a larger body’ is a weight inclusive, non stigmatising alternative to the terms of overweight, obesity
Physical activity	“Physical activity is anything that gets your body moving, makes you breathe faster and speeds up your heart rate. This can come in the form of incidental activities (e.g. cleaning, taking the stairs instead of the lift etc.), exercise, playing sports, dancing or muscle strengthening activities.”22
Science of obesity	The study of the diverse factors (such as biological, genetic, environmental, cultural, and social factors) that cause and impact the development and maintenance of obesity; the subsequent impact of excess weight on people, families, and communities; and the human body’s response to actions related to weight management.
Waist circumference	Waist circumference is the measurement of the narrowest point around the body, between the top of the hips and the bottom of the ribs. It is one way of estimating body fat stores in adults. A waist circumference over a certain threshold is associated with an increased risk of developing chronic conditions. These thresholds are different for men and women, and may be different for people of different ethnicities.23,24 Like BMI, waist circumference can be used as one part of a health and disease risk assessment, but is not a diagnostic tool on its own.
Weight bias	“Negative attitudes towards, and beliefs about other people because of their weight.”25
Weight cycling	“The loss and subsequent regain of body weight typically occurring in association with dieting.”26 Weight cycling has shown to have adverse health outcomes, including but not limited to: – Increased insulin resistance – Elevated body fat and abdominal fat accumulation – Increased risk of developing type 2 diabetes – Associated with higher cardiovascular disease mortality and morbidity
Weight discrimination	Actions against people who live in a larger body that can cause social exclusion and inequities.27
Weight stigma	“The social rejection and devaluation towards people who do not comply with current and prevailing social norms of “adequate” body weight and shape.”28
Wellbeing	“Wellbeing is a positive state experienced by individuals and societies. Similar to health, it is a resource for daily life and is determined by social, economic and environmental conditions. Wellbeing encompasses quality of life, as well as the ability of people and societies to contribute to the world in accordance with a sense of meaning and purpose.”29

References

¹ Henry Buchwald, “The Evolution of Metabolic/Bariatric Surgery,” Obesity Surgery 24 (2009), accessed October 28, 2022, doi: 10.1007/s11695-014-1354-3.

² “Obesity and Overweight,” World Health Organisation, accessed October 28, 2022,  https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight.

³ “Body Mass Index (BMI) and Waist Measurement,” Australian Government, accessed October 28, 2022, https://www.health.gov.au/topics/overweight-and-obesity/bmi-and-waist.

⁴ “Measuring Obesity,” Obesity Canada, accessed October 28, 2022, https://obesitycanada.ca/managing-obesity/measuring-obesity/.

⁵ “Child Growth Standards,” World Health Organisation, accessed October 28, 2022, https://www.who.int/tools/child-growth-standards.

⁶ “Growth Reference Data for 5-19 Years,” World Health Organisation, accessed October 28, 2022, https://www.who.int/tools/growth-reference-data-for-5to19-years.

⁷ World Health Organisation, Health Promotion Glossary of Terms 2021 (Geneva: World Health Organisation, 2021), 11, accessed October 28, 2022, https://www.who.int/publications/i/item/9789240038349.

⁸ National Health and Medical Research Council, Australian Dietary Guidelines (Canberra, A.C.T.: National Health and Medical Research Council, 2013).

⁹ “What Is the Difference between Disordered Eating & Eating Disorders?,” Eating Disorder Hope, accessed October 28, 2022, https://www.eatingdisorderhope.com/blog/eating-disorders-disordered-eating.

¹⁰ Department of Health, WA Healthy Weight Action Plan 2019-2024 (Perth, W.A.: Department of Health, 2019), https://www.health.wa.gov.au/Articles/U_Z/WA-Healthy-Weight-Action-Plan#:~:text=The%20WA%20Healthy%20Weight%20Action%20Plan%202019-2024%28hereafter%2C%20the,index%20range%29%20and%20those%20with%20overweight%20and%20obesity.

¹¹ “Understanding Disordered Eating and Eating Disorders,” Headspace, accessed October 28, 2022, https://headspace.org.au/explore-topics/for-young-people/eating-disorders/?gclid=Cj0KCQiA1NebBhDDARIsAANiDD1eNQTHu7fqmpu6wdg0zdb61StFHQiAfdgjTkR0ksfTwIwH96u5aWwaAu0QEALw_wcB.

¹² Jennifer L. Kuk et al., “Edmonton Obesity Staging System: Association with Weight History and Mortality Risk,” Applied Physiology, Nutrition, and Metabolism 36 (2011), accessed October 28, 2022, doi: 10.1139/h11-058.

¹³ Stasia Hadjiyannakis et al., “Edmonton Obesity Staging System for Pediatrics: A Proposed Clinical Staging System for Paediatric Obesity,” Paediatrics & Child Health 21 (2016), accessed October 28, 2022, doi: 10.1093/pch/21.1.21.

¹⁴ “Policies and Procedures : Patient and Family Centred Care,” Royal Children’s Hospital Melbourne, accessed October 28, 2022, https://www.rch.org.au/policy/public/Patient_and_Family_Centred_Care/.

¹⁵ World Health Organisation, Constitution of the World Health Organisation (Geneva: World Health Organisation, 1946), https://www.who.int/about/governance/constitution.

¹⁶ Department of Health, WA Health Promotion Strategic Framework (Perth, W.A.: Department of Health, 2017), https://www.health.wa.gov.au/~/media/Files/Corporate/Reports-and-publications/HPSF/wa_health_promotion_strategic_framework.pdf.

¹⁷ “Metabolic Syndrome: What Is Metabolic Syndrome?,” National Heart, Lung, and Blood Institute, accessed October 28, 2022, https://www.nhlbi.nih.gov/health/metabolic-syndrome.

¹⁸ “Healthy Eating and Diet,” Better Health Channel, accessed October 28, 2022, https://www.betterhealth.vic.gov.au/health/healthyliving/healthy-eating.

¹⁹ “Overweight and Obesity: An Interactive Insight,” Australian Institute of Health and Welfare, accessed October 28, 2022, https://www.aihw.gov.au/reports/overweight-obesity/overweight-and-obesity-an-interactive-insight/contents/causes.

²⁰ Person Centred Care,” Clinical Excellence Commission, accessed October 28, 2022, https://www.cec.health.nsw.gov.au/improve-quality/teamwork-culture-pcc/person-centred-care.

²¹ East Metropolitan Health Service, Shift. A Guide for Media and Communications Professionals (Perth, W.A.: East Metropolitan Health Service, 2020), https://www.health.wa.gov.au/~/media/Corp/Documents/Health-for/Health-Networks/Healthy-Weight-Action-Plan/Shift-A-guide-for-media-and-communications-professionals.pdf.

²² “About Physical Activity and Exercise,” Australian Government Department of Health and Aged Care, accessed October 28, 2022, https://www.health.gov.au/topics/physical-activity-and-exercise/about-physical-activity-and-exercise.

²³ “Overweight and obesity,” Australian Institute of Health and Welfare, accessed October 28, 2022, https://www.aihw.gov.au/reports/australias-health/overweight-and-obesity.

²⁴ “What is a healthy body weight?,” Heart Foundation, accessed October 28, 2022, https://www.heartfoundation.org.au/bundles/your-heart/healthy-body-weight.

²⁵ East Metropolitan Health Service, Shift. A Guide for Media and Communications Professionals (Perth, W.A.: East Metropolitan Health Service, 2020), https://www.health.wa.gov.au/~/media/Corp/Documents/Health-for/Health-Networks/Healthy-Weight-Action-Plan/Shift-A-guide-for-media-and-communications-professionals.pdf.

²⁶ Lauren E. Lissner  and Berit L. Heitmann, “Weight Management: Weight Cycling/Weight Change,” in Encyclopedia of Human Nutrition 3^rd Edition, ed. Benjamin Caballero (Amsterdam: Academic Press, 2013), 410-415, accessed October 28, 2022, https://www.sciencedirect.com/referencework/9780123848857/encyclopedia-of-human-nutrition#book-info.

²⁷ East Metropolitan Health Service, Shift. A Guide for Media and Communications Professionals (Perth, W.A.: East Metropolitan Health Service, 2020), https://www.health.wa.gov.au/~/media/Corp/Documents/Health- for/Health-Networks/Healthy-Weight-Action-Plan/Shift-A-guide-for-media-and-communications-professionals.pdf.

²⁸ Janet Tomiyama et al., “How and Why Weight Stigma Drives the Obesity ‘Epidemic’ and Harms Health,” BMC Medicine, 16 (2018), accessed October 28, 2022, https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-018-1116-5.

²⁹ World Health Organisation, Health Promotion Glossary of Terms 2021 (Geneva: World Health Organisation, 2021), 10, accessed October 28, 2022, https://www.who.int/publications/i/item/9789240038349.