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Basics

• Summary
• Start Here

Learn More

• Related Issues
• Specifics

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• Health Check Tools

Research

• Statistics and Research
• Clinical Trials
• Journal Articles

Resources

• Find an Expert

For You

• Children
• Teenagers
• Older Adults
• Patient Handouts

Summary

Do you know if your current weight is healthy? "Underweight", "normal", "overweight", and "obese" are all labels for ranges of weight. Obese and overweight mean that your weight is greater than it should be for your health. Underweight means that it is lower than it should be for your health. Your healthy body weight depends on your sex and height. For children, it also depends on your age.

A sudden, unexpected change in weight can be a sign of a medical problem. Causes for sudden weight loss can include

• Thyroid problems
• Cancer
• Infectious diseases
• Digestive diseases
• Certain medicines

Sudden weight gain can be due to medicines, thyroid problems, heart failure, and kidney disease.

Good nutrition and exercise can help in losing weight. Eating extra calories within a well-balanced diet and treating any underlying medical problems can help to add weight.

Start Here

• Assessing Your Weight (Centers for Disease Control and Prevention) Also in Spanish
• Assessing Your Weight and Health Risk (National Heart, Lung, and Blood Institute)

Related Issues

• Antidepressants and Weight Gain (Mayo Foundation for Medical Education and Research) Also in Spanish
• Body Image (Department of Health and Human Services, Office on Women's Health) Also in Spanish
• Can Beta Blockers Cause Weight Gain? (Mayo Foundation for Medical Education and Research) Also in Spanish
• Normal Weight Obesity: A Hidden Health Risk? (Mayo Foundation for Medical Education and Research) Also in Spanish
• Thyroid and Weight (American Thyroid Association) Also in Spanish

Specifics

• About BMI for Adults (Centers for Disease Control and Prevention) Also in Spanish
• Health Risks of Overweight and Obesity (National Institute of Diabetes and Digestive and Kidney Diseases)
• Preventing Weight Gain (Centers for Disease Control and Prevention) Also in Spanish
• Unexplained Weight Loss (Mayo Foundation for Medical Education and Research) Also in Spanish

Health Check Tools

• Calculate Your Body Mass Index (National Heart, Lung, and Blood Institute) Also in Spanish

Statistics and Research

• Overweight and Obesity Statistics (National Institute of Diabetes and Digestive and Kidney Diseases)
• Why Do We Get Middle-Age Spread? (National Institutes of Health) Also in Spanish

Clinical Trials

• ClinicalTrials.gov: Body Mass Index (National Institutes of Health)
• ClinicalTrials.gov: Body Weight (National Institutes of Health)
• ClinicalTrials.gov: Body Weight Changes (National Institutes of Health)
• ClinicalTrials.gov: Obesity (National Institutes of Health)
• ClinicalTrials.gov: Thinness (National Institutes of Health)

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

• Article: The Weight of Obesity in Immunity from Influenza to COVID-19.
• Article: Fasting alters the gut microbiome reducing blood pressure and body weight...
• Article: Body Weight Changes During Pandemic-Related Shelter-in-Place in a Longitudinal Cohort Study.
• Body Weight -- see more articles

Find an Expert

• Find a Nutrition Expert (Academy of Nutrition and Dietetics)
• National Institute of Diabetes and Digestive and Kidney Diseases

Children

• About Child and Teen BMI (Centers for Disease Control and Prevention) Also in Spanish
• Birth Weight: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
• Overweight and Obesity (For Parents) (Nemours Foundation) Also in Spanish
• What "Being Overweight" Means (For Kids) (Nemours Foundation) Also in Spanish

Teenagers

• Healthy Weight Gain for Teens: A Guide for Parents (Boston Children's Hospital)
• What's the Right Weight for My Height? (For Teens) (Nemours Foundation) Also in Spanish

Older Adults

• Healthy Weights for Healthy Older Adults (Academy of Nutrition and Dietetics)

Patient Handouts

• Body mass index (Medical Encyclopedia) Also in Spanish
• Growth chart (Medical Encyclopedia) Also in Spanish
• Overweight (Medical Encyclopedia) Also in Spanish
• Weight gain - unintentional (Medical Encyclopedia) Also in Spanish
• Weight loss - unintentional (Medical Encyclopedia) Also in Spanish