Table of ContentsView AllTable of ContentsSelf-Checks/At-Home TestingLabs and TestsDifferential DiagnosisFrequently Asked QuestionsNext in Obesity GuideWhat Is Obesity Treatment Like?
Table of ContentsView All
View All
Table of Contents
Self-Checks/At-Home Testing
Labs and Tests
Differential Diagnosis
Frequently Asked Questions
Next in Obesity Guide
Diagnosingobesityinvolves much more than simply stepping onto a scale. In fact, a thorough evaluation of a person’s weight status is a complex procedure that involves taking into consideration many factors and the use of various tools and diagnostic tests:body mass index(BMI), waist circumference measurement, physical exams, and lab tests to check for comorbidities.
Verywell / Laura Porter
In the last 40 years, obesity has become a major worldwide health issue. “Obesity is a serious concern because it is associated with poorer mental health outcomes, reduced quality of life, and the leading causes of death in the U.S. and worldwide,” says the Centers for Disease Control and Prevention (CDC).
The most successful strategy for obesity treatment involves early diagnosis and intervention. Studies have shown that getting a formal diagnosis of obesity is more likely to result in weight loss (compared to those who are never diagnosed).
Body Mass Index (BMI)
For adults 20 and older, a BMI from 18.5 to 24.9 (kilograms of weight per squared meter of height) is called a healthy weight.
BMI is a dated, flawed measure. It does not take into account factors such asbody composition, ethnicity, sex, race, and age. Even though it is a biased measure, BMI is still widely used in the medical community because it’s an inexpensive and quick way to analyze a person’s potential health status and outcomes.
What Are the Different Classes of Obesity?
Waist Circumference Measurement
Fat stored in the abdominal area is called visceral fat, which may further increase the risk of diseases such asheart diseaseanddiabetes. Among people with a BMI in the range of 25–34.9, a waist measurement of over 35 inches in women and over 40 inches in men is associated with an increased risk for disease.
It can be useful to keep an eye on this measurement since changes in waist circumference are an independent predictor of risk, regardless of overall weight, if you’re within the healthy weight to overweight range on the BMI scale.
The waist measurement should be considered at least annually. A person can perform a waist measurement as a self-test to screen for a high risk of obesity. However, other measurements (such as BMI) need to be taken into account as well since waist circumference thresholds are not reliable for patients with a BMI greater than 35. Also, waist circumference may not be a reliable indicator of abdominal fat for all ethnicities, genders, and age groups.
Other Diagnostic Measures
Other diagnostic measures used to identify or evaluate obesity include:
It’s important to understand the significance of seeking professional help when it comes to diagnosing childhood, adolescent, or adult obesity.
Diagnostic testing for obesity and overweight conditions may involve some lab tests to evaluate the extent of how the condition has impacted a person’s overall health and to check for signs of underlying disease. The lab tests your healthcare provider will order depend on many factors, such as your risk factors for obesity-related diseases and current symptoms.
Lab tests may include:
Diagnosing Childhood Obesity
To diagnose childhood obesity, a healthcare provider will use a growth chart to evaluate how a child’s weight and height compare to other kids of the same age and sex. For example, a child who is considered in the 90th percentile weighs more and has a higher BMI than 90% of other children of that same age and sex.
The CDC has established growth charts to diagnose overweight and obese children. A child in the 85th–94th percentile is deemed overweight and one who is in the 95th percentile or above is considered obese.
Because growth patterns and body frames can differ drastically from one child to the next, pediatricians take several factors into consideration when diagnosing a child’s weight status. These include:
Lab tests that may be ordered when a child is suspected of being overweight include:
Diagnosing Adolescent Obesity
For diagnosing obesity in adolescents, the BMI scale is used in conjunction with comparing adolescents with other teens of the same age and sex. Adolescents in the 95thpercentile or more (for age and sex) or those with a BMI of 30 or more are considered obese.
Teenagers in this category are given a complete medical examination, which includes:
According to Stanford Children’s Health, adolescents with a BMI between the 85th and 95th percentile or those with a BMI equal to 30 are automatically put into a risk category in which they will receive a second screening in five areas.These include:
Morbid Obesity Diagnosis
The BMI scale is the primary method for differentiating between obesity andmorbid obesity. According to the World Health Organization (WHO), obesity is defined as having a BMI equal to or greater than 30.
A person is considered morbidly obese when body weight is 100 pounds over ideal levels for his or her height, with a BMI of 40 or more. Morbid obesity is also diagnosed with a BMI of 35 or more for a person who has an obesity-related illness such as diabetes or high blood pressure.
There are many factors to consider as part of a thorough obesity diagnosis other than just a person’s weight status. Knowing what to expect and how to ensure an accurate weight evaluation may be the difference between a correct diagnosis—leading to early intervention—and a misdiagnosis of a person’s weight status.
Accuracy of the BMI Rating Scale
BMI is not always a completely accurate measurementwhen it comes to obesity diagnosis.Some individuals, namely athletes who have a large percentage of muscle mass, can throw off the accuracy of the scale. This is because athletes have very high body mass, but very little body fat content.
There have been several studies aimed at evaluating the accuracy of BMI calculations compared to other techniques to measure body fat. Although some of the study results have varied, there is strong evidence that standard BMI ratings underestimate body adipose (fat) composition.
According to the American Medical Association’sAMA Journal of Ethics, “A BMI equal to or greater than 30 has a sensitivity of 50% in detecting excess adiposity, meaning that half of those with a high body fat percent will not be called obese. Furthermore, because BMI calculations use total weight in the denominator, some lean subjects with preserved muscle mass may be labeled overweight.”
In addition, BMI measurements do not consider overall fat distribution, meaning that those with slightly overweight or normal weight, who have, for example, high levels of abdominal fat (visceral fat) may not be considered at risk according to BMI criteria.
Tests That May Improve the Accuracy of an Obesity Diagnosis
Body fat can be measured using a variety of methods. In addition to BMI, these measurements can help to improve the accuracy of an obesity diagnosis:
The bioelectrical impedance tool pinches the skin at various locations of the body, pulling the skin away from the underlying muscle tissue, to measure the width of the fat tissue.
Several skinfolds are usually measured, including:
A skinfold test and other diagnostic tools are often used in conjunction with the BMI scale to more accurately identify the signs and symptoms of obesity.
Frequently Asked QuestionsThere are genetic factors that increase the risk for certain people to become obese. However, there are ways to combat the genetic link and there are a lot of otherrisk factors leading to obesity.Toprevent obesity, start as early as possible and make smart dietary decisions such as reducing sugar and saturated fat, avoiding processed foods, and drinking lots of water. Getting regular exercise is also important to maintain a healthy weight. Limiting stress and getting plenty of sleep also help to reduce the risk of becoming obese.
There are genetic factors that increase the risk for certain people to become obese. However, there are ways to combat the genetic link and there are a lot of otherrisk factors leading to obesity.
Toprevent obesity, start as early as possible and make smart dietary decisions such as reducing sugar and saturated fat, avoiding processed foods, and drinking lots of water. Getting regular exercise is also important to maintain a healthy weight. Limiting stress and getting plenty of sleep also help to reduce the risk of becoming obese.
How Obesity Is Treated
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Adult Obesity Causes & Consequences.Centers for Disease Control and Prevention.Lopez-Jimenez F, Miranda W.Diagnosing Obesity: Beyond BMI.Virtual Mentor.2010;12(4):292-298. doi:10.1001/virtualmentor.2010.12.4.cprl1-1004.Centers for Disease Control and Prevention.BMI frequently asked questions.Guidelines on Overweight and Obesity: National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases.Managing Overweight and Obesity in Adults: Systematic Evidence Review from the Obesity Expert Panel.Stanford Children’s Health.Obesity in teens.Centers for Disease Control and Prevention.Behavior, environment, and genetic factors all have a role in causing people to be overweight and obese.Centers for Disease Control and Prevention.Preventing weight gain.Additional ReadingHealthy Weight. Adult BMI Calculator. Centers for Disease Control and Prevention.Lopez-Jimenez F, Miranda W.Diagnosing Obesity: Beyond BMI.Virtual Mentor.2010;12(4):292-298. doi:10.1001/virtualmentor.2010.12.4.cprl1-1004.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Adult Obesity Causes & Consequences.Centers for Disease Control and Prevention.Lopez-Jimenez F, Miranda W.Diagnosing Obesity: Beyond BMI.Virtual Mentor.2010;12(4):292-298. doi:10.1001/virtualmentor.2010.12.4.cprl1-1004.Centers for Disease Control and Prevention.BMI frequently asked questions.Guidelines on Overweight and Obesity: National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases.Managing Overweight and Obesity in Adults: Systematic Evidence Review from the Obesity Expert Panel.Stanford Children’s Health.Obesity in teens.Centers for Disease Control and Prevention.Behavior, environment, and genetic factors all have a role in causing people to be overweight and obese.Centers for Disease Control and Prevention.Preventing weight gain.Additional ReadingHealthy Weight. Adult BMI Calculator. Centers for Disease Control and Prevention.Lopez-Jimenez F, Miranda W.Diagnosing Obesity: Beyond BMI.Virtual Mentor.2010;12(4):292-298. doi:10.1001/virtualmentor.2010.12.4.cprl1-1004.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Adult Obesity Causes & Consequences.Centers for Disease Control and Prevention.Lopez-Jimenez F, Miranda W.Diagnosing Obesity: Beyond BMI.Virtual Mentor.2010;12(4):292-298. doi:10.1001/virtualmentor.2010.12.4.cprl1-1004.Centers for Disease Control and Prevention.BMI frequently asked questions.Guidelines on Overweight and Obesity: National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases.Managing Overweight and Obesity in Adults: Systematic Evidence Review from the Obesity Expert Panel.Stanford Children’s Health.Obesity in teens.Centers for Disease Control and Prevention.Behavior, environment, and genetic factors all have a role in causing people to be overweight and obese.Centers for Disease Control and Prevention.Preventing weight gain.
Adult Obesity Causes & Consequences.Centers for Disease Control and Prevention.
Lopez-Jimenez F, Miranda W.Diagnosing Obesity: Beyond BMI.Virtual Mentor.2010;12(4):292-298. doi:10.1001/virtualmentor.2010.12.4.cprl1-1004.
Centers for Disease Control and Prevention.BMI frequently asked questions.
Guidelines on Overweight and Obesity: National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases.Managing Overweight and Obesity in Adults: Systematic Evidence Review from the Obesity Expert Panel.
Stanford Children’s Health.Obesity in teens.
Centers for Disease Control and Prevention.Behavior, environment, and genetic factors all have a role in causing people to be overweight and obese.
Centers for Disease Control and Prevention.Preventing weight gain.
Healthy Weight. Adult BMI Calculator. Centers for Disease Control and Prevention.Lopez-Jimenez F, Miranda W.Diagnosing Obesity: Beyond BMI.Virtual Mentor.2010;12(4):292-298. doi:10.1001/virtualmentor.2010.12.4.cprl1-1004.
Healthy Weight. Adult BMI Calculator. Centers for Disease Control and Prevention.
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