Obesity in adults

Last reviewed: 7 Jan 2023
Last updated: 09 Nov 2022



History and exam

Key diagnostic factors

  • height
  • weight
More key diagnostic factors

Other diagnostic factors

  • waist circumference
  • comorbid conditions
Other diagnostic factors

Risk factors

  • hypothyroidism
  • hypercortisolism
  • age ≥40 years
  • peri- and postmenopause
  • prior pregnancy
  • married
  • sleep deprivation
  • history 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
More risk factors

Diagnostic investigations

1st investigations to order

  • clinical exam
More 1st investigations to order

Investigations to consider

  • FBC
  • serum transaminases
  • thyroid function tests
  • ECG
  • abdominal ultrasound scan
  • polysomnography (sleep study)
More investigations to consider

Treatment algorithm


BMI ≥30 kg/m²; or else BMI ≥27 kg/m² with an obesity-related comorbidity

BMI ≥40 kg/m²; or else BMI ≥35 kg/m² with significant comorbidities and dietary attempts at weight control have been ineffective



Constantine T. Frantzides, MD, PhD, FACS
Constantine T. Frantzides

Director, Chicago Institute of Minimally Invasive Surgery (CIMIS)

Director, Laparoscopic and Bariatric Fellowship Program

Clinical Professor of Surgery, University of Illinois




CTF declares that he has no competing interests.

Mark A. Carlson, MD, FACS
Mark A. Carlson

Professor, Department of Surgery

Professor, Department of Genetics, Cell Biology and Anatomy (courtesy)

Director, Center for Advanced Surgical Technology (CAST)

University of Nebraska Medical Center

Staff Physician, Surgery Department

Omaha VA Medical Center




MAC declares that he has no competing interests.

Kelsey R. Tieken, MD
Kelsey R. Tieken

General Surgery Resident

University of Nebraska Medical Center




KRT declares that she has no competing interests.


Dr Constantine T. Frantzides, Dr Mark A. Carlson, and Dr Kelsey R. Tieken would like to gratefully acknowledge Dr Minh B. Luu and Dr Scott N. Welle, previous contributors to this topic.


MBL and SNW declare that they have no competing interests.

Peer reviewers

Carel Le Roux, MRCP, PhD, FRCPath

Consultant in Metabolic Medicine

Imperial College London

Charing Cross Hospital




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




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




EHL declares that he has no competing interests.

  • Differentials

    • Hypothyroidism, primary
    • Hypothyroidism, central
    • Cushing's syndrome
    More Differentials
  • Guidelines

    • Obesity: identification, assessment and management
    • AGA clinical practice guidelines on intragastric balloons in the management of obesity
    More Guidelines
  • Patient leaflets

    Obesity - diet and exercise

    Obesity - drugs and surgery

    More Patient leaflets
  • Calculators

    Body Mass Index (Quetelet's index)

    More Calculators
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