Obesity in adults

Last reviewed: July 2019

Last updated: May 2019

Summary

Presentation of obesity may range from asymptomatic to presentation complicated by multiple comorbidities, including cancer, CAD, diabetes, hypertension, gout, obstructive sleep apnoea, and osteoarthritis.

The definitive test for the diagnosis of obesity remains the BMI (obesity is defined as a BMI ≥30 kg/m^2).

Central or abdominal obesity has a stronger association with obesity-related comorbidity than peripheral (i.e., subcutaneous) obesity, so waist circumference may be a better indicator of the risk for obesity-related comorbidity than BMI.

The mainstay of non-surgical treatment of obesity is diet and exercise, with psychological therapy as a recommended adjunct for all patients. The risk of complications is low, but the overall efficacy and durability of this combination is poor.

Drug therapy may be considered as an adjunct to diet and exercise (never as monotherapy) for patients with a BMI ≥30 kg/m^2. Pharmacotherapy has modest short-term efficacy but a high attrition rate and a lack of long-term efficacy.

Surgical treatment is an option for patients with BMI ≥40 kg/m^2, or ≥35 kg/m^2 with significant comorbidities. In general, weight-reductive surgery works through manipulation of the stomach or small bowel, or a hybrid of both. Potential complications are numerous.

Definition

Obesity can be defined as a chronic adverse condition due to an excess amount of body fat. While there are many methods to determine the relative amount of body fat, the most widely used method to determine obesity is the BMI, defined as weight divided by height squared ([weight in kg]/[height in m]^2). [1] Jensen MD, Ryan DH, Apovian CM, et al; American College of Cardiology/American Heart Association Task Force on Practice Guidelines; Obesity Society. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. Circulation. 2014 Jun 24;129(25 suppl 2):S102-38. [2] [3]

History and exam

Key diagnostic factors

height
weight

Full details

Other diagnostic factors

waist circumference
hip circumference
comorbid conditions

Full details

Risk factors

hypothyroidism
hypercortisolism
age ≥40 years
peri- and postmenopause
prior pregnancy
married
sleep deprivation
hx of tobacco smoking
less formal education
poor in utero nutrition
low socioeconomic status
sedentary lifestyle
television watching and video games >2 to 3 hours daily
diet high in sugar, cholesterol, fat, and fast food
heavy alcohol intake (>2 drinks per day)
binge-eating disorder
night eating syndrome
leptin deficiency
corticosteroid therapy
antidepressant therapy
antipsychotic therapy
beta-blocker therapy
adjuvant breast cancer therapy
psychiatric diagnosis

Full details

Diagnostic investigations

1st investigations to order

clinical exam

Full details

Investigations to consider

FBC
serum transaminases
thyroid function tests
ECG
abdominal ultrasound scan
polysomnography (sleep study)

Full details

Treatment algorithm

ONGOING

BMI ≥30 kg/m^2; or else BMI ≥27 kg/m^2 with an obesity-related comorbidity

BMI ≥40 kg/m^2; or else BMI ≥35 kg/m^2 with significant comorbidities and dietary attempts at weight control have been ineffective

Contributors

Authors VIEW ALL 

Constantine T. Frantzides, MD, PhD, FACS

Director

Chicago Institute of Minimally Invasive Surgery

Director

Minimally Invasive Surgery Fellowship Program

St. Francis Hospital

Clinical Professor of Surgery

University of Illinois

Chicago

Disclosures

CTF declares that he has no competing interests.

Minh B. Luu, MD, FACS

Associate Director, General Surgery Residency Program

Rush Medical College

Associate Professor of Surgery

Department of General Surgery

Rush University Medical Center

Chicago

Disclosures

MBL declares that he has no competing interests.

Acknowledgements

Dr Constantine T. Frantzides and Dr Minh B. Luu would like to gratefully acknowledge Dr Scott N. Welle and Dr Mark A. Carlson, previous contributors to this topic. SNW declares that he has no competing interests. MAC declares that he is the author of the Daily Diet Score, a freely available online weight loss method.

Peer reviewers VIEW ALL 

Carel Le Roux, MRCP, PhD, FRCPath

Consultant in Metabolic Medicine

Imperial College London

Charing Cross Hospital

London

Disclosures

CLR declares that he has no competing interests.

Arya M. Sharma, MD, PhD, FRCPC

Professor of Medicine

Chair for Obesity Research & Management

University of Alberta

Royal Alexandra Hospital

Edmonton

Canada

Disclosures

AMS declares that he has no competing interests.

Edward H. Livingston, MD, FACS

Chair in Surgery

Division of Gastrointestinal and Endocrine Surgery

University of Texas

Southwestern Medical Center

Dallas

Disclosures

EHL declares that he has no competing interests.

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Obesity in adults

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Treatment algorithm

BMI ≥30 kg/m^2; or else BMI ≥27 kg/m^2 with an obesity-related comorbidity

BMI ≥40 kg/m^2; or else BMI ≥35 kg/m^2 with significant comorbidities and dietary attempts at weight control have been ineffective

Contributors

Authors VIEW ALL 

Constantine T. Frantzides, MD, PhD, FACS

Disclosures

Minh B. Luu, MD, FACS

Disclosures

Acknowledgements

Peer reviewers VIEW ALL 

Carel Le Roux, MRCP, PhD, FRCPath

Disclosures

Arya M. Sharma, MD, PhD, FRCPC

Disclosures

Edward H. Livingston, MD, FACS

Disclosures

Differentials

Guidelines

Patient leaflets

Calculators

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