Glossary of Terms

Reviewed by: HU Medical Review Board | Last reviewed: August 2023

Obesity is a complex medical condition. There can be multiple reasons why a person lives with obesity. That makes knowing all the key terms a little challenging.

To help, we have defined common terms related to obesity.


Abdominal circumference

A measurement of the area around a person’s waist. This measurement can help assess the person’s risk of metabolic disease. Based on the measurement technique, results may vary.1


The process by which nutrients in digested food move from the lower part of the small intestine into the bloodstream.2

Adipose tissue

Tissue that is primarily made up of fat cells.2

Adjustable gastric banding

A surgical procedure that allows patients to feel full with smaller amounts of food. An example is a Lap-Band®. This is where a belt is placed around the stomach, separating it into two pouches. The belt is filled with fluid in order to slow the flow of food from the upper to the lower pouch.3



Relating to the treatment of obesity.2

Bariatric healthcare provider

A healthcare provider who uses a broad treatment plan to meet individual needs and preferences around weight loss. A plan may include nutrition, exercise, behavior changes, and medicines. Weight loss surgery may also be advised.4

Body mass index (BMI)

A method that uses a person’s weight and height to measure their proportion of excess weight. It is calculated by dividing the person’s weight (in kilograms) by the square of their height (in meters), then multiplying by 703. BMI can vary by age and sex.2,5,6



Relating to the blood vessels and heart.2

Childhood obesity

Obesity that occurs in children. It can lead to symptoms such as anxiety and depression. It also can lead to obesity in adulthood.6


A part of the large intestine that spans from the end of the small intestine to the rectum.2


Reasons why a healthcare professional may not recommend a treatment due to certain circumstances or health conditions.2



A licensed and registered health professional who specializes in the area of food and nutrition. They use their expertise to assess, plan, and implement personalized dietary plans for individuals or groups to promote optimal health, manage medical conditions, and achieve specific nutritional goals.7


The process by which the body breaks down food so nutrients can be absorbed by the stomach and upper small intestine.2


Expanding or opening a passage.2

Divided gastric bypass surgery

A surgical operation used to manage clinically severe obesity.2

Dumping syndrome

A reaction that results from ingesting high-sugar or high-fat foods or liquids after bariatric surgery. Symptoms may include nausea, lightheadedness, upset stomach, vomiting, and diarrhea.2


The first 12 inches of small intestine below the stomach. In the duodenum, bile and pancreatic fluids flow from the liver and pancreas.2


Eating disorder

A complex and serious mental health condition characterized by abnormal eating habits, thoughts, and behaviors related to food, body image, and weight. Examples include anorexia, bulimia, and binge eating disorder.8

Early-onset severe obesity

Extreme obesity that occurs before the age of 5.9

Excess weight

The difference between a patient's weight and what is considered a healthy weight.2


Fatty liver disease

A condition where excessive fat is released in the liver, which can lead to liver damage. Obesity heightens the risk of fatty liver disease.10,11



Bile deposits in the gallbladder that result from high blood cholesterol levels.9

Gastric bypass surgery

A procedure in which the surgeon uses part of the stomach to form a small stomach pouch and reroutes a part of the small intestine.2


Relating to the entire digestive tract.2


A surgical procedure that changes the shape of the stomach. It may be recommended in cases of morbid obesity.2

Genetic factors

Factors in a person’s genes that can determine their risk for obesity.12


A hormone produced in the stomach and duodenum. It stimulates secretion of growth hormone and increases appetite.3

Gut hormones

Hormones involved in regulating food intake.6

Gut microbiome

The microorganisms that live inside the digestive tract. The gut microbiome affects the absorption and digestibility of ingested calories.6



Weakness in the tissue of the abdominal wall that results in a visible bulge.2


High blood pressure.2



A section of the small intestine that is important for absorption. It is about 10 feet long.2

Intragastric balloons

Soft and durable silicone spheres that can be placed in the stomach to help people feel full while eating less food.3



The 10 feet of small intestine responsible for digestion.2



A hormone that signals the brain about the quantity of stored fat produced in fat cells, the placenta, and the gut.6


Metabolic operations

Surgeries that can help people lose weight by changing their body’s response to calories. Metabolic surgery changes the secretion of gut hormones, which reduces feelings of hunger.6


The process your body uses to turn calories into energy. This energy fuels all of the body’s functions.10

Monogenic obesity

A rare form of obesity related to a single gene.6

Morbid obesity

A body mass index (BMI) of 40 or more. These weight levels may be considered life-threatening.2,6

Multidisciplinary bariatric program

A treatment approach for clinically severe obesity that includes many types of approaches. These can include surgical, internal medicine, therapy, and nutrition.2


Non-metabolic operations

Surgeries that can lead to significant weight loss without changing the body’s normal metabolic processes.3


A healthcare professional specializing in the field of nutrition and dietetics. They are trained to assess and analyze a person’s dietary habits and nutritional needs, providing personalized guidance and recommendations to promote better health, prevent diseases, and achieve specific health goals.7



A manageable condition resulting from excessive weight or adipose tissue. Common contributors to obesity include genetics, hormones, medicines, and environment.1,2,5,6


The narrowing of a part of the gastrointestinal tract, which slows down the normal passage of food or waste.2


Polygenic factors

The relationship between genetic factors and environmental factors that may cause obesity.6


Relating to the lungs.2


A type of treatment method for mental health challenges or disorders. Also called talk therapy.2


Severe obesity

Being more than 100 pounds over a healthy body weight or having a BMI greater than 40. Severe obesity can lead to many other health problems.12

Sleep deprivation

A significant lack of sleep. Not getting enough sleep can lead to weight gain or trouble losing weight.12

Social determinants of health

The conditions in which people live that affect their health outcomes. Social determinants of health can influence daily decisions such as food choices and physical activity. They vary based upon a person’s environment.13


Sterile staples used in surgery to connect tissues together inside the body. They are often permanent.2

Syndromic obesity

Obesity that is caused by changes in certain genes and that is associated with certain other collections of physical characteristics (syndromes). Associated syndromes include Down syndrome and Prader-Willi syndrome.6


Type 2 diabetes

A disorder of glucose and insulin metabolism. Having obesity can raise a person’s risk of developing type 2 diabetes.2,10



A BMI score of under 18.5.1


Vertical banded gastroplasty

A rare surgical procedure used to treat morbid obesity. It changes the shape of the stomach to restrict food intake.2


Weight bias

The negative attitudes and beliefs society holds toward people who are perceived as being overweight or having obesity. It is a form of discrimination that can happen in various settings, including healthcare, education, employment, and social interactions.14

Weight stigma

The shame and disgrace associated with being overweight or living with obesity. Weight stigma is the result of weight bias. It often leads to social exclusion, body shaming, and even verbal or physical abuse.14

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