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Women and Being Underweight

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Women and Being Underweight

Am I Underweight?

Overweight, Underweight, Just Right

Image by TheVisualMD

How Do I Know If I’m Underweight?

You can use the body mass index (BMI) to find out whether your weight is in a healthy or unhealthy range. BMI is a tool to estimate body fat. Find your BMI by typing your height and weight into this BMI calculator from the Centers for Disease Control and Prevention.

Women with a BMI of less than 18.5 are considered underweight. The average woman's height is 5 feet, 4 inches. If you weigh 107 pounds or less at this height, you are considered underweight with a BMI of 18.4. A healthy weight range for that woman would be 108 to 145 pounds.

BMI is just one way to measure healthy weight. Some women have a low, but still healthy weight. Talk to your doctor or nurse about what is a healthy weight for you.

Source: Office on Women's Health (OWH), U.S. Department of Health and Human Services

Additional Materials (4)

Women and Underweight

North Carolina Department of Health and Human Services

Top Questions About Healthy Weight and Women

Office on Women's Health, U.S. Department of Health and Human Services

3:54

Recovering From An Eating Disorder

As/Is/YouTube

1:31

Underweight? Obese? Your Body Mass Index Will Tell You

Evergreen Wellness/YouTube

Body Mass Index

Body Mass Index

Also called: BMI, Quetelet Index

Body mass index (BMI) is an estimate of body fat calculated from a person's height and weight. It is used to screen for weight categories that may lead to health problems. The higher your BMI, the higher your risk for certain diseases such as heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers.

Body Mass Index

Also called: BMI, Quetelet Index

Body mass index (BMI) is an estimate of body fat calculated from a person's height and weight. It is used to screen for weight categories that may lead to health problems. The higher your BMI, the higher your risk for certain diseases such as heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers.

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Use the slider below to see how your results affect your health.
kg/(m<sup>2</sup>)
18.5
25
30
35
40
Your result is Underweight.
A BMI of less than 18 indicates that you are underweight, so you may need to put on some weight. You are recommended to ask your doctor or a dietician for advice.
Related conditions

BMI is calculated the same way for both adults and children. The calculation is based on the following formulas:

Measurement Units

Formula and Calculation

Kilograms and meters (or centimeters)

Formula: weight (kg) / [height (m)]²

With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared. Because height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height in meters.

Example: Weight = 68 kg, Height = 165 cm (1.65 m)
Calculation: 68 ÷ (1.65)² = 24.98

Pounds and inches

Formula: weight (lb) / [height (in)]² x 703

Calculate BMI by dividing weight in pounds (lbs) by height in inches (in) squared and multiplying by a conversion factor of 703.

Example: Weight = 150 lbs, Height = 5’5″ (65″)
Calculation: [150 ÷ (65)²] x 703 = 24.96

The correlation between the BMI and body fatness is fairly strong, but even if 2 people have the same BMI, their level of body fatness may differ.
In general,
- At the same BMI, women tend to have more body fat than men.
- At the same BMI, Blacks have less body fat than do Whites, and Asians have more body fat than do Whites
- At the same BMI, older people, on average, tend to have more body fat than younger adults.
- At the same BMI, athletes have less body fat than do non-athletes.
The accuracy of BMI as an indicator of body fatness also appears to be higher in persons with higher levels of BMI and body fatness. While, a person with a very high BMI (e.g., 35 kg/m²) is very likely to have high body fat, a relatively high BMI can be the results of either high body fat or high lean body mass (muscle and bone). A trained healthcare provider should perform appropriate health assessments in order to evaluate an individual’s health status and risks.
People who have obesity are at increased risk for many diseases and health conditions, including the following:
- All-causes of death (mortality)
- High blood pressure (Hypertension)
- High LDL cholesterol, low HDL cholesterol, or high levels of triglycerides (Dyslipidemia)
- Type 2 diabetes
- Coronary heart disease
- Stroke
- Gallbladder disease
- Osteoarthritis (a breakdown of cartilage and bone within a joint)
- Sleep apnea and breathing problems
- Chronic inflammation and increased oxidative stress
- Some cancers (endometrial, breast, colon, kidney, gallbladder, and liver)
- Low quality of life
- Mental illness such as clinical depression, anxiety, and other mental disorders
- Body pain and difficulty with physical functioning

Normal reference ranges can vary depending on the laboratory and the method used for testing. You must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."

Additional Materials (20)

Normal BMI for Kids

Body mass index (BMI) is one way of finding out if your child (age 2-19) is at a healthy weight. There is no universal normal range for kids as there is for adults. That's because the normal amount of body fat changes with age and height and also depends on whether the child is a boy or a girl.

Image by TheVisualMD

Body Mass Index

8 women with the same Body Mass Index rating (BMI - 30) but with different weight distribution and abdominal volume, so they have different Body Volume Index(BVI) ratings.

Image by Richard2902 at en.wikipedia

Body Mass Index

A woman's two bare feet standing on a bathroom scale with a glass-topped surface on a tile floor. Toenails are painted red. Image supports content advising readers to set goals regarding improvements to their health and well-being, including maintaining a healthy weight and nutritious diet, and getting adequate exercise

Image by Bill Branson, NIH

Body Mass Index

Image by BruceBlaus

Woman on scale

A woman's two bare feet standing on a bathroom scale with a glass-topped surface on a tile floor. Toenails are painted red. Image supports content advising readers to set goals regarding improvements to their health and well-being, including maintaining a healthy weight and nutritious diet, and getting adequate exercise

Image by TheVisualMD

Weight Loss | How To Calculate BMI | StreamingWell.com

Video by streamingwell/YouTube

Why BMI Is BS

Video by Seeker/YouTube

Body Mass Index (BMI)

Obesity and its health risks are a growing problem in the United States. It is estimated that more than two-thirds of adults are either overweight (10 to 30 pounds heavier than recommended) or obese (more than 30 pounts heavier than recommended). The number of overweight and obese school-age children is also on the rise. This is especially alarming given what is known about how obesity increases the risk of diabetes, high blood pressure, and cardiovascular disease. A way to measure obesity is the BMI or body mass index, a measurement of weight categories based on height.

Image by TheVisualMD

BMI Calculator For Women And Men & What is BMI ?

Video by KidandParent/YouTube

Roux en-Y Gastric Bypass, with Introduction on Body Mass Index, Animation.

Video by Alila Medical Media/YouTube

Calculate your own body mass index | Miscellaneous | Heatlh & Medicine | Khan Academy

Video by khanacademymedicine/YouTube

The Skinny on Obesity (Ep. 1): An Epidemic for Every Body

Video by UCTVTips/YouTube

Our Supersized Kids

Video by KSPS Public TV/YouTube

Four body types to show classes of body mass index

Drawing of four body types to show classes of body mass index.

Image by NIDDK Image Library

Breaking Down Under Pressure

When you’re obese (body mass index of over 30), you greatly raise your risk of developing OA, especially of the knee. Women who are overweight women have four times the risk and overweight men have five times the risk of developing knee OA as people of normal body weight.

Image by TheVisualMD

Body mass index chart

Graph of body mass index showing the various divisions.

Image by InvictaHOG/Wikimedia

Underweight - Body image rating scale for men and women.

Figure 1. Body image rating scale for men and women. Images 1 through 5 represent people who are underweight, images 6 through 9 represent people of normal weight, images 10 through 13 represent overweight people, and images 14 through18 represent obese people (11).

Image by CDC / Ettarh R et al.

Overweight Man Holding Beer Bottle

Three-dimensional visualization reconstructed from scanned human data. Lateral view of head and torso of overweight man with large belly holding beer bottle; the skeleton and internal organs are visible. Regular beer drinkers tend to be overweight or obese, due to the high number of calories alcohol contributes to their diet. A body mass index (BMI) is a measure of body fat calculated by dividing a person's body weight in kilograms by the square of their height in meters, and is considered useful in determining health risks associated with being overweight or obese. A normal body mass index (BMI) is considered to be under 25, while overweight is under 30; anything greater than a value of 30 is considered to be obese. Overweight and obese individuals are at increased risk for many health conditions and diseases such as hypertension, high cholesterol, diabetes, heart disease, stroke, sleep problems, gallbladder disease, sexual dysfunction, and some cancers.

Image by TheVisualMD

Obese Woman, cross section

Traditionally, obesity has been defined as a weight at least 20% above ideal weight. More recent guidelines call for classifying obesity by using the body mass index (BMI). BMI is calculated based on your height and weight. However, BMI may classify as obese some people who aren't overweight but who are heavily muscled or big-boned. It also doesn't take into account the person's age. Waist-to-hip ratios (WHR) may be a better indication of disease risk, because they indicate if you have a lot of dangerous visceral fat inside your abdomen. Some doctors feel it's possible to be classified as obese and still be physically fit.

Image by TheVisualMD

US Navy 110426-N-00332-114 Students measure the height and body weight of fourth and fifth grade students from Lindenwood Elementary School

NEWPORT NEWS, Va. (April 26, 2011) Logistics Specialist 1st Class Alhaji M. Kabba, a command fitness leader aboard the aircraft carrier USS Theodore Roosevelt (CVN-71), measures the height and body weight of a student from Lindenwood Elementary School. Sailors assigned to Theodore Roosevelt spent 10 weeks mentoring the students about the Navy's culture of fitness to prepare them for participation in the Navy Physical Fitness Assessment. (U.S. Navy photo by Mass Communication Specialist Seaman Cory C. Asato/Released)

Image by U.S. Navy photo by Mass Communication Specialist Seaman Cory C. Asato/Wikimedia

Normal BMI for Kids

TheVisualMD

Body Mass Index

Richard2902 at en.wikipedia

Body Mass Index

Bill Branson, NIH

Body Mass Index

BruceBlaus

Woman on scale

TheVisualMD

4:22

Weight Loss | How To Calculate BMI | StreamingWell.com

streamingwell/YouTube

3:02

Why BMI Is BS

Seeker/YouTube

Body Mass Index (BMI)

TheVisualMD

1:05

BMI Calculator For Women And Men & What is BMI ?

KidandParent/YouTube

3:55

Roux en-Y Gastric Bypass, with Introduction on Body Mass Index, Animation.

Alila Medical Media/YouTube

7:21

Calculate your own body mass index | Miscellaneous | Heatlh & Medicine | Khan Academy

khanacademymedicine/YouTube

12:16

The Skinny on Obesity (Ep. 1): An Epidemic for Every Body

UCTVTips/YouTube

30:00

Our Supersized Kids

KSPS Public TV/YouTube

Four body types to show classes of body mass index

NIDDK Image Library

Breaking Down Under Pressure

TheVisualMD

Body mass index chart

InvictaHOG/Wikimedia

Underweight - Body image rating scale for men and women.

CDC / Ettarh R et al.

Overweight Man Holding Beer Bottle

TheVisualMD

Obese Woman, cross section

TheVisualMD

US Navy 110426-N-00332-114 Students measure the height and body weight of fourth and fifth grade students from Lindenwood Elementary School

U.S. Navy photo by Mass Communication Specialist Seaman Cory C. Asato/Wikimedia

Causes

Woman suffering from anorexia nervosa

Image by Wellcome Trust

What Causes Women to Be Underweight or to Lose Weight Suddenly?

Some women are naturally thinner than others. But certain health problems, certain medicines, or other serious problems can lead to chronic (long-term) underweight or sudden weight loss. These include:

Health problems that affect metabolism, such as overactive thyroid or diabetes
Health problems that affect the digestive system, such as celiac disease or Crohn's disease
Other health problems, such as viral hepatitis, cancer, COPD, or Parkinson's disease
A lack of appetite due to stress, illness, or substance use
Medicines that may cause nausea or lack of appetite
Eating disorders, such as anorexia
Over-exercising, such as for athletic training
Age. Underweight can especially be a problem for older women who may have loss of appetite, problems chewing, or a health problem.
Genes. Underweight can run in families.

Also, there may be a link between underweight in childhood and developing an eating disorder in adolescence.

Source: Office on Women's Health (OWH), U.S. Department of Health and Human Services

Additional Materials (4)

1:47

How Your Thyroid Impacts Your Weight

Lee Health/YouTube

3:09

Is Anorexia In Your Genes?

Seeker/YouTube

29:12

Diabulimia: The World's Most Dangerous Eating Disorder

BBC Three/YouTube

2:07

Malnutrition and IBD

Crohn's & Colitis Foundation/YouTube

Risks

Cross Sections of Normal Bone and Osteoporosis bone

Image by TheVisualMD

How Does Being Underweight Affect a Woman’s Health?

Underweight raises your risk for serious health problems. Some women have a low, but still healthy weight. But if you have experienced sudden weight loss or are not eating enough to keep your body working, you may develop serious health problems, including:

Problems with your menstrual cycle. A regular period is a sign of good health. Losing too much weight can cause periods to be less regular or stop completely. This can happen if your body fat drops so low that you stop ovulating, or releasing an egg from an ovary each month. This is especially true if you are losing weight because you are not eating enough or because you are exercising too much, which may be signs of an eating disorder like anorexia nervosa.
Problems getting pregnant. Problems with your menstrual cycle can make it harder to get pregnant, especially if your period stops completely. If you do not get a period, then you are probably not ovulating, or releasing an egg from an ovary each month.
Osteoporosis. Underweight increases your risk of osteoporosis later in life. Osteoporosis is a condition that causes bones to become weak and break easily.
Malnutrition. Malnutrition means your body is not getting enough vitamins and minerals to do what it needs to do. This can cause serious health problems, such as a weaker immune system and anemia. Anemia happens when your blood cannot carry enough oxygen to your body because of a lack of iron. If you have anemia, you may feel dizzy, lightheaded, weak, or tired.
Depression. Studies show that depression is more common in women who are underweight than women who are at a healthy weight.

Women who are underweight may also be more likely to die early than people of normal weight.⁶ Women who are underweight earlier in adulthood may also experience menopause sooner than women who stayed a normal weight.

Source: Office on Women's Health (OWH), U.S. Department of Health and Human Services

Additional Materials (4)

1:58

What Are Side Effects of Purging? | Eating Disorders

Howcast/YouTube

2:32

What are signs of malnutrition in adults? How can I help someone to eat who doesn't want to?

IntermountainParents/YouTube

8:36

Bone Density and Celiac Disease

Mayo Clinic/YouTube

1:21

Health Topics: How does being underweight affect pregnancy?

Nebraska Methodist Health System/YouTube

Gaining Weight

What are the symptoms of binge eating disorder?

Image by Maria Raquel Cochez

How Can I Gain Weight in a Healthy Way?

Talk to your doctor or nurse about an eating plan that can help you gain weight in a healthy way. To gain weight in a healthy way, you should focus on getting enough nutrients — calories, vitamins, and minerals — for your body to work correctly. To reach a healthy weight, you should eat foods from all of the food groups with a calorie amount that is healthy for your current weight. Your doctor or nurse can tell you how quickly to gain weight in a safe and healthy way. Gaining weight suddenly, or by eating a lot of sweet or fatty foods, is not healthy.

If you need to gain weight because of an eating disorder, work with your doctor or nurse to gain weight safely and treat the eating disorder. If the eating disorder is not treated, it may come back or continue and cause health problems. Gaining weight too suddenly, with an eating disorder, can cause serious heart problems and other health concerns.

Because many Americans are overweight, there are many resources geared toward losing weight. But some of these resources can also provide guidance for you to gain weight in a healthy way

Source: Office on Women's Health (OWH), U.S. Department of Health and Human Services

Additional Materials (4)

3:52

Meal Planning: Healthy Weight & Nutrition

NationwideChildrens/YouTube

1:05

Start New Habits for Being Active and Eating Healthy

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)/YouTube

1:05

Eat Healthy Even When You Don’t Have Time to Cook

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)/YouTube

2:22

Healthy Snacking for Weight Gain

Columbia University Department of Surgery/YouTube

Exercising

Woman Running with Visible Skeletal, Muscular and Cardiovascular Systems

Image by TheVisualMD

Should I Stop Exercising If I’m Underweight or Losing Weight Too Quickly?

Maybe. People who are underweight due to an eating disorder should not exercise unless their doctor tells them to. Physical activity is important for your health, muscle strength, balance, and flexibility. Your doctor or nurse can help you develop an exercise plan that is healthy and safe for a person of your current weight.

If you normally do high-intensity aerobic workouts, your doctor or nurse may talk to you about more moderate or less vigorous aerobic, strength training, and flexibility exercises.

Source: Office on Women's Health (OWH), U.S. Department of Health and Human Services

Additional Materials (4)

1:46

Study: Underweight Female Runners Move Likely To Get Stress Fractures

Ohio State Wexner Medical Center/YouTube

2:23

Warm Water Exercise Arthritis and Osteoporosis Victoria

Musculoskeletal Australia/YouTube

1:56

Strengthening Your Bones Through Exercise

Lee Health/YouTube

3:10

Physical, Mental, And Overall Health Benefits Of Regular Exercise - How Exercise Improves Health

Whats Up Dude/YouTube

Getting Help

Woman on scale

Image by TheVisualMD

When Should I Talk to a Doctor or Nurse About My Weight?

If you are worried about your weight, talk to your doctor or nurse.

Your weight can affect your health. Your weight can also make it harder to get pregnant. Talk to your doctor or nurse if you are underweight and have period problems or symptoms of malnutrition, such as extreme tiredness, headaches, or hair loss.

Your doctor or nurse will ask you questions and may do tests to learn more about what is causing your symptoms or weight loss. Your doctor or nurse may suggest making changes in your eating and exercise habits, depending on the cause of your weight loss.

Source: Office on Women's Health (OWH), U.S. Department of Health and Human Services

Additional Materials (4)

5:29

Eating Disorders and Pregnancy | What It's Like

Today's Parent/YouTube

3:13

Child Malnutrition - What? How? And when to Refer..

iheed/YouTube

2:02

Fertility & Eating Disorders: Important Study Reveals Need for Compassion

Eating Disorder Hope/YouTube

5:35

Eating Disorders and Pregnancy

Eating Disorders and Pregnancy: Training for healthcare professionals/YouTube

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