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Basics

• Summary
• Start Here
• Diagnosis and Tests
• Prevention and Risk Factors
• Treatments and Therapies

Learn More

• Related Issues
• Specifics
• Genetics

See, Play and Learn

• Health Check Tools
• Test Your Knowledge

Research

• Statistics and Research
• Clinical Trials
• Journal Articles

Resources

• Find an Expert

For You

• Children
• Teenagers
• Men
• Women
• Older Adults
• Patient Handouts

Summary

Obesity means having too much body fat. It is different from being overweight, which means weighing too much. The weight may come from muscle, bone, fat, and/or body water. Both terms mean that a person's weight is greater than what's considered healthy for his or her height.

Obesity happens over time when you eat more calories than you use. The balance between calories-in and calories-out differs for each person. Factors that might affect your weight include your genetic makeup, overeating, eating high-fat foods, and not being physically active.

Obesity increases your risk of diabetes, heart disease, stroke, arthritis, and some cancers. If you have obesity, losing even 5 to 10% of your weight can delay or prevent some of these diseases. For example, that means losing 10 to 20 pounds if you weigh 200 pounds.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Start Here

• About Obesity (Centers for Disease Control and Prevention)
• Obesity (Endocrine Society)
• Obesity (Mayo Foundation for Medical Education and Research)
• What Are Overweight and Obesity? (National Heart, Lung, and Blood Institute) Also in Spanish

Diagnosis and Tests

• Assessing Your Weight and Health Risk (National Heart, Lung, and Blood Institute)
• Bioimpedance Scale (Johns Hopkins Medicine)
• Body Mass Index Table (National Heart, Lung, and Blood Institute)
• How Well Does Body Mass Index Correlate with Excess Fat? (Harvard Medical School)
• Obesity Screening (National Library of Medicine) Also in Spanish

Prevention and Risk Factors

• Aim For a Healthy Weight (National Heart, Lung, and Blood Institute)
• Balance Food and Activity (National Heart, Lung, and Blood Institute) Also in Spanish
• Overweight and Obesity: Causes and Risk Factors (National Heart, Lung, and Blood Institute)
• Staying Active at Any Size (National Institute of Diabetes and Digestive and Kidney Diseases) Also in Spanish
• Weight Management and Healthy Living Tips (National Institute of Diabetes and Digestive and Kidney Diseases)

Treatments and Therapies

• Obesity and Exercise (Obesity Medicine Association)
• Understanding the Dietary Inflammatory Index and Its Uses (Obesity Medicine Association)
• Weight Control: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
• Weight Loss Surgery: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish

Related Issues

• Disability and Obesity (Centers for Disease Control and Prevention) Also in Spanish
• Obesity and Anesthesia (American Society of Anesthesiologists)
• Obesity and Cancer (National Cancer Institute) Also in Spanish
• Obesity and Hypertension: Mechanisms, Risks, and Treatment (Obesity Medicine Association)
• Obesity and Sleep Apnea: Understanding the Connection (Obesity Medicine Association)
• Obesity and Your Digestive Health (American College of Gastroenterology) - PDF

Specifics

• Health Risks of Overweight and Obesity (National Institute of Diabetes and Digestive and Kidney Diseases) Also in Spanish
• Obesity (American Psychological Association) Also in Spanish
• Obesity Hypoventilation Syndrome (National Heart, Lung, and Blood Institute) Also in Spanish
• Sarcopenic Obesity: Causes, Diagnosis and Treatment (Obesity Medicine Association)

Genetics

• Congenital leptin deficiency: MedlinePlus Genetics (National Library of Medicine)
• Leptin receptor deficiency: MedlinePlus Genetics (National Library of Medicine)
• Proopiomelanocortin deficiency: MedlinePlus Genetics (National Library of Medicine)

Health Check Tools

• Adult BMI Calculator (Centers for Disease Control and Prevention) Also in Spanish
• Calculate Your BMI (National Heart, Lung, and Blood Institute)

Test Your Knowledge

• Test Your Weight Loss Knowledge (Medical Encyclopedia) Also in Spanish
• Weight Loss Myths & Facts Quiz (Medical Encyclopedia) Also in Spanish

Statistics and Research

• Adult Obesity Prevalence Maps (Centers for Disease Control and Prevention)
• Diet--Not a Lack of Exercise--Is Main Driver of Obesity, Study Finds (Harvard School of Public Health)
• FastStats: Obesity and Overweight (National Center for Health Statistics)
• Obesity and Severe Obesity Prevalence in Adults: United States, August 2021--August 2023 (Centers for Disease Control and Prevention)
• Overweight and Obesity Statistics (National Institute of Diabetes and Digestive and Kidney Diseases)

Clinical Trials

• ClinicalTrials.gov: Obesity (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Metabolic Health and Heterogenous Outcomes of Prenatal Interventions: A Secondary Analysis...
• Article: Digital outdoor exercise program for obese patients with type 2 diabetes...
• Article: Myokine Circulating Levels in Postmenopausal Women with Overweight or Obesity: Effects...
• Obesity -- see more articles

Find an Expert

• Find a Nutrition Expert (Academy of Nutrition and Dietetics)
• Find an Obesity Medicine Provider (Obesity Medicine Association)
• National Heart, Lung, and Blood Institute
• National Institute of Diabetes and Digestive and Kidney Diseases

Children

• Obesity in Children: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish

Teenagers

• Dealing with Feelings When You're Overweight (For Teens) (Nemours Foundation) Also in Spanish

Men

• Belly Fat in Men: Why Weight Loss Matters (Mayo Foundation for Medical Education and Research) Also in Spanish

Women

• Belly Fat in Women: Taking -- and Keeping -- It off (Mayo Foundation for Medical Education and Research) Also in Spanish
• Pregnancy and Obesity: Know the Risks (Mayo Foundation for Medical Education and Research)
• Weight and Obesity (Department of Health and Human Services, Office on Women's Health)

Older Adults

• Obesity Care and Treatment (National Council on Aging)

Patient Handouts

• Body mass index (Medical Encyclopedia) Also in Spanish
• Health risks of obesity (Medical Encyclopedia) Also in Spanish
• Obesity (Medical Encyclopedia) Also in Spanish
• Obesity hypoventilation syndrome (OHS) (Medical Encyclopedia) Also in Spanish