Authors as Published

Elena Serrano, Extension Specialist, Department of Human Nutrition, Foods, and Exercise, Virginia Tech; and Kathryn Branstad, former graduate student, Virginia Tech

Being underweight is not the same as being thin or slender. Some children have a naturally slight build and maintain it with a well-balanced diet and physical activity. This is normal and healthy. However, true underweight may be a sign of dietary, health, or emotional problems. 
Some children are naturally small, which is different than underweight

How do I know if my child is underweight?

Weighing your child may not give you enough information to determine if he or she is underweight. If you are concerned that your child may be underweight, consult your child’s doctor. A physician or other health professional can compare your child’s weight and height to growth charts developed by the Centers for Disease Control (CDC). A child is underweight if his or her BMI-for-age-and-gender is less than the 5th percentile. BMI, or body mass index, is defined as weight divided by height times height (kg/m2).

What are some concerns for underweight children?

There are several possible reasons for being underweight: not consuming enough food, an underlying illness, stress, obsessive exercise, lack of interest in eating, or a sudden growth spurt. An under-nourished child is more likely to become sick. The child may feel weak or tired, and have trouble focusing and concentrating. He or she may have stunted growth or a delay in the onset of puberty. It has been estimated that 12 million children live in food-insecure households, meaning that they have limited availability of nutritious and safe foods.

If a child has no interest in eating, it could be a sign of anxiety, a food allergy causing discomfort after meals, high amounts of caffeine, an excessive fear of being overweight, or even an eating disorder. In any case, it is extremely important to work with your child’s doctor or health professional to help determine what is going on and how to address it.

What can I do to help my child?

If your doctor recommends weight gain, the main goal will be to get your child to take in more calories. Continue to promote physical activity as part of a normal routine. If your child has been playing actively, have him or her rest for at least 15 minutes before meal times.

What should my child eat?

Offer extra calories that are rich in important nutrients. Avoid letting your child fill upon on empty calories, such as candy and soft drinks, or high-fat foods from fast-food restaurants. Begin by planning meals and snacks with calorie-dense foods from each food group of the MyPyramid. Limit snacking just before mealtime, as this may curb appetite. Avoid caffeine; promote healthy drinks, such as water and milk. Tailor your food choices to foods that your child enjoys and will eat.


Ideas for Foods from the Different Food Groups

Grains: whole grain bread and bagels, granola bars, pancakes, crackers, cornbread, pasta

Vegetables: baked French fries, sweet potatoes, peas, corn, squash, broccoli

Fruit: canned fruit in syrup, dried fruits, fresh fruit

Milk: flavored milk, cheese, cottage cheese, yogurt, pudding

Meat and Beans: eggs, peanut butter, tuna fish, chicken, hamburgers, salmon, nuts, bean soups, kidney beans, chick peas (hummus). Nuts are a great source of protein and healthy fats, but may cause choking in young children; some children may be allergic to them.

Calorie-Dense Combinations:

  • Peanut butter and jelly sandwich
  • Macaroni and cheese
  • Crackers with hummus
  • Fruit smoothies made with yogurt
  • Baked potato with broccoli and cheese
  • Beef and barley soup and cornbread
  • French toast or pancakes with ham and fruit

When preparing foods, provide heart-healthy sources of added fat, such as vegetable oils in place of butter, margarine, and sour cream. For example, make mashed potatoes with vegetable oil. Any high-calorie supplement should come from your doctor or dietitian along with a care plan. 

Choose nutrient-dense foods for your child

How much should my child eat?

Encourage frequent eating and snacking. Six small meals may be easier to eat than three larger meals. Your child should eat as much as he or she can without feeling uncomfortable. Do not pressure your child to eat. Rather, offer plentiful meals and snacks to your child throughout the day. When your child goes to school, give him or her plastic sandwich bags filled with snack foods, such as granola bars, crackers, dried fruit (like raisins), carrots, nuts, and jerky. At first, your child may not be accustomed to eating so much. Offer positive support for any positive changes. Realize that changes may not take place overnight. Be patient.

How can I create a positive body image in my underweight child?

Remember that each child is unique. Each child’s body shape is unique. Children come in different sizes, shapes, and weights. They also grow at different rates. Every body is a good body.

Do not weigh your child frequently. Home should be a comfortable and accepting place for children, not stressful. Your doctor may request regular visits to monitor your child’s progress. You can use this opportunity to obtain information about your child’s weight. Also, be sensitive about discussions focusing on weight.

A healthy weight is a weight that can be maintained healthfully, insuring that children are well nourished, active, and have a positive attitude about their body and size.

Where can I get more information?

If you have any questions or concerns about your child’s weight, contact your physician or a registered dietitian. They can work with you to determine if your child is at a healthy weight and how to proceed if there are any concerns.

Virginia Cooperative Extension offers educational and cooking classes for parents, childcare providers, and children on nutrition. Visit the Virginia Cooperative Extension website at to locate your nearest Extension Agent for more information on food, nutrition, and health programs and resources.

For more resources and information:

Visit to obtain an individualized eating plan for everyone in your family. The website also has links to other diet and physical information and a webpage for kids which includes My Pyramid Blast Off game and tips for families.

Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.

Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.

Publication Date

May 1, 2009