The Basics

Written by the doctors and editors at UpToDate

Why is my child's weight gain important?

Babies and children need to gain enough weight to grow and develop normally.

Some children are smaller than others, but if they are gaining weight as expected over time, they can be healthy. But not gaining weight at the expected rate can lead to problems later in life. These can include learning problems or problems with the body's infection-fighting system (called the "immune system").

Some children do not gain enough weight starting at birth. Others gain enough weight for a while, but then slow down or stop gaining weight.

How do I know if my child is not gaining enough weight?

Your child's doctor or nurse will tell you.

Babies and children should have regular doctor's appointments. These happen more frequently for babies and toddlers, then usually once a year after age 3. Checking your child's weight is part of these visits.

At each visit:

● Your child will be weighed.

● The doctor or nurse will compare your child's weight with their weight at the last visit.

● They will also compare your child's weight with other children of the same age and sex.

If your child isn't gaining enough weight, the doctor or nurse will want to figure out why. They will treat the cause and work with you to help your child gain more weight.

Why might a baby or child might not gain enough weight?

Reasons can include:

● Being born too early – Most babies gradually catch up, but some do not.

● Not getting enough food – For example, some babies have trouble sucking at the breast or bottle. Or caregivers might not feed their baby often enough.

● Having a medical problem that affects the stomach, mouth, throat, or heart

● Changes or stress in the home or family

● Having a hard time paying attention when they eat

Why isn't my child gaining weight?

To figure this out, the doctor or nurse will do an exam and ask you questions about your child's eating habits. They might watch your baby or child eat to check how they swallow. They might ask you to keep track of all of the food your child eats (form 1). Tell the doctor or nurse if you sometimes run out of food or have to buy less food because you don't have enough money. They can connect you with help.

Tell the doctor or nurse if your child:

● Has vomiting, diarrhea, or constipation

● Does not eat certain foods

● Drinks much more than they eat

This information can help the doctor figure out why your child is not gaining enough weight. They might also order some tests.

Who will help my child gain weight?

Your child's doctor or nurse will work with you to make a plan to help your child gain weight. They might recommend that you also work with other experts, such as a:

● Lactation consultant – This is a specialist that can give help and advice on breastfeeding.

● Dietitian – This is an expert on food and eating.

Most children can be treated at home. But some children need to stay in the hospital for a short time. In the hospital, doctors can:

● Do tests and watch your child closely to figure out why they are not gaining enough weight

● Start treating your child

How can I help my child gain enough weight?

There are some things you can do to help your child get the nutrition they need (table 1). You can change:

● What your child eats – You can help your child gain weight by feeding them foods with a lot of calories. Talk with a doctor, nurse, or dietitian about the right way to do this. They might recommend adding extra calories to your baby's feedings.

If your child is older, they might recommend that you:

● Add healthy foods with a lot of calories to their meals – Examples include cheese, oils, butter, cream, and sour cream. Avoid or limit foods without a lot of nutrients, like candy, soda, and processed snacks.

● Give them a vitamin every day.

● How often your child eats – Babies might need more feedings each day to gain weight. Older children might need to eat every 2 to 3 hours, and have 3 meals and 3 snacks a day.

● Where and how your child eats – Making changes to the area where your child eats might help them eat more. For example, some children eat more when the whole family eats together or when meals are fun. Other children eat more when they eat in a quiet place with only 1 person for company. Try to avoid other distractions during meals, like phones and TV.

Sometimes, people wonder if their child should avoid or limit activity to help them gain weight. Your child does not need to avoid activity. Being active is healthy for children, even if they are slow to gain weight.

Are there other treatments that can help?

Sometimes, other types of treatments can help. These can include:

● Medical treatments – Some children need to be treated for health problems that can keep them from gaining enough weight.

● Physical or occupational therapy – Some children have problems with their body or behavior that can make it hard for them to eat enough food. Experts called "physical therapists" or "occupational therapists" can work with children to improve these types of problems.

● Family help – Some children do not eat enough because of problems at home. A family might not have enough food or be stressed. Or a caregiver might be too sick to take care of a child. Your child's doctor or nurse can work with you to find help for these types of problems.

When should I follow up with the doctor or nurse?

Your child's doctor or nurse will follow up with you regularly. During each visit, they will weigh your baby or child and talk with you. Tell them if you have questions or are having any problems with treatment.

All topics are updated as new evidence becomes available and our peer review process is complete.

This topic retrieved from UpToDate on: Apr 04, 2026.

Topic 15450 Version 11.0

Release: 34.3.4 - C34.92

Images

form 1: Diet diary

A diet diary is a way to keep track of the foods you eat each day.

Graphic 58605 Version 8.0