Patient education: Slow weight gain in infants and children (Beyond the Basics)

OVERVIEW — 

During infancy and childhood, children gain weight and grow in height more rapidly than at any other time in life. However, some children gain weight and grow more slowly than others. In some cases, slower weight gain is a normal and expected variation because of the child's genetic makeup. In other cases, it is related to premature birth, an underlying medical problem, or undernutrition, which may occur for a variety of reasons. Abnormally slow weight gain is sometimes called weight faltering or "failure to thrive."

It is important to evaluate children with slow weight gain to determine whether it is a sign of undernutrition or an underlying medical problem that requires treatment. If undernutrition is severe and prolonged, it can affect a child's linear growth (height), cause difficulties with learning, or weaken their immune system.

HOW TO MONITOR GROWTH IN CHILDREN

Growth charts — Slow weight gain is defined by comparing a child's weight gain to other children who are the same age and sex. "Normal" ranges for weight are based on the weight of thousands of children. Standard growth charts are published by the Centers for Disease Control and Prevention (CDC) and the World Health Organization; these charts can be used to track growth for all children. Other charts indicate whether a child's weight is proportionate to their height; this is done with weight-for-length charts (for children less than two years) or body mass index (BMI) charts (for children two years and older). The charts used in the United States are available through the links below.

●Children less than two years old:

•For girls – Weight-for-age chart and weight-for-length chart

•For boys – Weight-for-age chart and weight-for-length chart

●Children two years and older:

•For girls – Weight-for-age chart and BMI chart

•For boys – Weight-for-age chart and BMI chart

If your baby was born prematurely, you can use the same growth charts, but adjust the age by the amount they were born prematurely until your child is two years old. For example, if your baby was born eight weeks early and is now six months old, plot the growth chart as if they are four months old. Children with particular genetic syndromes may require special growth charts. For example, the CDC website has growth charts for children with Down syndrome, which can be used to show your child's growth compared with other children with Down syndrome.

Definition of slow weight gain — Weight gain normally follows a predictable course from infancy through adolescence. This means that a child's weight increases parallel to any of the curved percentile lines on the growth chart. Some movement up or down across the curved percentile lines is normal, especially during the first two years of life. For most healthy children, their weight percentile is somewhat similar to their height percentile (for example, both weight and height are near the same percentile of the growth chart). The percentiles don't have to match exactly, because some children are naturally thinner or heavier than others.

A child probably has slow weight gain if their:

●Weight is below the bottom curve on the weight-for-age growth chart (which represents approximately the 2^nd percentile) or drops across percentile curves.

●Weight percentile is much lower than their height percentile (for example, weight is at the 5^th percentile and height at the 40^th percentile).

●Weight-for-length is below the 5^th percentile (for children less than two years), or BMI is below the 5^th percentile (for children two years and older). Being below the 5^th percentile on these charts means that a child is very thin, while being above the 85^th percentile means that they are overweight.

Some children do not gain weight normally from birth, while other children gain weight normally for a while and then slow or stop gaining weight. Weight is the first indicator in undernutrition. This means that if a child is undernourished, their weight gain slows before their length or height growth slows.

CAUSES OF SLOW WEIGHT GAIN — 

Slow weight gain has many possible causes. The causes can be grouped in these general categories:

●Inadequate intake of calories (a measure of dietary energy)

●Malabsorption (not absorbing an adequate amount of nutrients)

●Having a medical condition that requires a higher-than-normal amount of calories

Slow weight gain can occur as a result of a medical problem, a developmental or behavioral difference, lack of adequate food, stresses in the home (eg, financial or other challenges), or, most frequently, a combination of these problems. Common causes of slow weight gain for each age group are described below.

●Prenatal

•Prematurity – Babies who were born prematurely are naturally smaller than full-term babies. After birth, they often grow slowly at first; then, if they are healthy, they gradually catch up.

•Small for gestational age at birth (or "intrauterine growth restriction," which is similar).

•The birth mother had certain types of infections during pregnancy.

•The birth mother took certain medications or toxins during pregnancy – For example, certain seizure medicines, high alcohol intake, smoking tobacco, or street drugs.

•In addition, high caffeine consumption during pregnancy has been linked with slightly lower birth weight.

●Birth to 6 months

•Breastfeeding problems – For example, problems with the baby's attachment to the nipple ("latching on"), nipple pain, or not enough milk production.

•Underfeeding – For example, not feeding frequently enough or not offering enough at each feed, or incorrect formula preparation (adding too much water to the formula). These issues might be due to difficulty getting enough food or formula due to cost or other problems, or being unsure how much the baby needs to eat.

•Feeding interactions – For example, a caregiver doesn't feed the baby when they are hungry, or the baby often gags or vomits ("spits up" or "spills") during feeding and the caregiver assumes that they are full rather than trying again.

•Difficulty sucking or other physical problems – For example, problems that affect the child's ability to suck and swallow (cleft palate or neurologic problems) or digest (cystic fibrosis or intestinal problems).

•Medical problems that increase the child's caloric needs – For example, congenital heart disease.

•Food allergies or intolerance (eg, to cow's milk or other proteins). This can occur in either breastfed or formula-fed babies.

●7 to 12 months

•Feeding interactions – For example, the baby refuses to eat new foods and the caregiver does not offer that food again. Or the caregiver pressures or forces the baby to eat certain foods.

•Problems with sucking or swallowing – For example, problems with the child's mouth or nerves can make it hard for them to learn to chew or swallow textured foods.

•Starting solid foods too late – For example, not offering solid foods until seven months or later.

•Underfeeding – For example, not getting enough nutritious solid foods.

•Medical problems – For example, food allergies, intestinal parasites, or congenital heart disease.

●Over 12 months

•Behavioral problems – For example, a toddler who is very picky or easily distracted at meal time.

•Sensory-based feeding disorders in children with developmental differences. This is more common in children with autism spectrum disorder.

•Home stress – For example, divorce, conflict at home, financial problems, a new sibling, or death in the family. This type of stress might make it harder for a parent or caregiver to focus on feeding and nurturing the child.

•Underfeeding – For example, not having enough food due to cost or other problems, or not offering enough food due to fear of overfeeding or following a restricted diet.

•Food choices – For example, the child drinks too much milk or juice so they feel too full to eat other foods. Children who eat a very limited range of foods may develop vitamin and mineral deficiencies.

•Medical problems – For example, celiac disease or food allergies.

EVALUATION FOR SLOW WEIGHT GAIN — 

If a baby or child slows or stops gaining weight, it is important to try to determine and treat the underlying cause. The first step is a complete diet history, medical history, and physical examination. Most children will not require blood testing or imaging tests, although testing may be recommended in certain situations.

A typical history for slow weight gain includes the following:

●Foods and feeding history – The health care provider will ask you details about your child's diet. They may ask you to keep a record of everything your child eats and drinks for a few days (form 1). This can help determine if your child is eating an adequate amount and variety of food for their age and body size.

●You should mention if your child:

•Often has diarrhea, abdominal pain, or constipation that may be worsened by certain foods.

•Has vomiting or rumination (which means that the child swallows, regurgitates, then re-swallows food).

•Avoids foods with particular textures (eg, hard or crunchy) – This might be a sign of a problem with chewing/swallowing or a food aversion.

•Avoids types or groups of food – It is common for toddlers to be picky and avoid certain foods because of taste or texture or because the food is unfamiliar. Rarely, avoiding certain foods (eg, milk, wheat) can be a sign of a food allergy or intolerance.

•Certain behaviors – Children with behavioral rigidity (insistence on sameness) or sensory aversions are often unwilling to eat a typical variety of foods. This is more common in children with autism spectrum disorder.

•Drinks large amounts of milk, fruit juices, or low-calorie liquids – Drinking these beverages may decrease the child's appetite and result in the child eating less solid foods, which contain more calories. Drinking large amounts of milk also can lead to iron deficiency anemia.

•Follows a restricted diet – Tell the health care provider if your child has any diet restrictions (eg, if they follow a vegetarian, lactose-free, or gluten-free diet). Also mention if you have eliminated foods from the child's diet due to concern about the effects of these foods (eg, that the foods might be causing abdominal pain, diarrhea, or hyperactivity).

●Other medical signs or symptoms – It important to mention if your child has a history of other medical problems, including:

•Fever

•Diarrhea

•Blood or mucous in the stools

•Abdominal pain

•Rash

•Sores in the mouth

•Swelling, pain, or redness of the joints

•Headache

•Eye pain

•History of prematurity

•Family history of bowel disease or food intolerance

●Family and household information – Important information about the household and family may include:

•Family and caregivers – Who lives in the child's house, and frequent caregivers and visitors.

•Household stress – Any recent changes or stresses in the household (eg, divorce, illness, death, new sibling), or if anyone in the household or close family has a medical or mental health problem, including an eating disorder or depression.

•Food insecurity – Tell the health care provider if you have any problems with food supply or food "insecurity." For example, if you sometimes worry that the food would run out before you get money to buy more, or if there are times that your food doesn't last and you don't have money to get more. Although these questions can be difficult to answer, it is important to be honest. This information is important to help figure out the cause of the child's slow weight gain. Also, the health care provider might have suggestions for community resources or finding less expensive foods that are nutritious.

TREATMENT OF SLOW WEIGHT GAIN — 

The goal of treatment is to ensure that your child has adequate nutrition to "catch up" to a healthy weight. There is a wide range of healthy weights for a particular age. Catch-up growth may require changes to the child's diet, feeding schedule, or feeding environment. You can work with a health care clinician to develop a plan that meets the needs of your child and family.

The type of treatment needed depends on the cause of the slow weight gain, any underlying medical problems, and the severity of the situation.

●Most children with slow weight gain can be managed at home with help from the child's care team. In some cases, this might include specialty providers such as a dietitian, occupational or speech therapist, social worker, nurse, developmental-behavioral pediatrician, early intervention specialist, child-life specialist, pediatric gastroenterologist, or child psychiatrist.

●Children who are very underweight are usually hospitalized initially. While in the hospital, the care team can monitor your child's diet, feeding behaviors, and weight. If your child has signs of a medical problem, the care team might also do tests during the hospitalization.

Nutrition therapy — Nutrition therapy is the primary treatment for children with slow weight gain. The goal of nutritional therapy is to enable "catch-up" weight gain, which is usually two to three times the normal rate of weight gain for the child's age. The best way to increase your child's caloric intake (also known as dietary energy) depends on their age and nutritional status. The child's care team can provide individualized recommendations for their diet, which may include adding a multivitamin. Multivitamins won't help your child gain weight, but they can provide vitamins and minerals that might be missing from your child's usual diet.

For babies — Babies between zero and four months require frequent breast milk (or formula) feedings, typically 8 to 12 per day; older infants typically require four to six feedings per day. The strategy for increasing your baby's intake depends on their diet.

●Breastfed babies – If your baby is breastfeeding and has slow weight gain, the first step is to determine whether the mother's body is making enough milk, if the baby is having problems getting the milk (milk transfer), or both. The health care provider or a lactation consultant can help determine the cause and advise how to solve it. Breastfeeding frequently and pumping helps the breasts make more milk. You can learn more by reading the chapter available through this link. (See "Patient education: Common breastfeeding problems (Beyond the Basics)".)

In some cases, the health care clinician may suggest adding something to the breast milk for some or all feeds. This is called "fortifying" the milk. To do this, the mother uses a pump to extract breast milk, then adds a specific amount of formula powder or liquid concentrate. For your baby's safety, always follow a recipe provided by a health care clinician or dietitian. (See "Patient education: Pumping breast milk (Beyond the Basics)".)

●Formula-fed babies – If you feed your baby formula, you can increase the number of calories in the formula by adding less water to powder or liquid concentrate or by adding a calorie supplement, such as a specialized carbohydrate powder or corn oil. For your baby's safety, always follow a recipe provided by a health care clinician or dietitian.

Do not feed your baby plant-based milks (eg, soy, almond, rice, coconut) other than a commercial soy-based infant formula. Plant based milks do not provide enough protein, calcium, vitamin D, and other nutrients to meet the needs of a baby. Similarly, homemade "formulas" are not safe for babies, including those made from a recipe that seems healthy. If you are considering feeding your baby a homemade formula, talk to the doctor or a specialized pediatric dietitian first.

●Solid foods – For older infants (usually four months and older), the health care provider may advise adding rice cereal or formula powder to pureed foods to increase their caloric intake.

For older children

●General strategies – If your child is older than one year, you can add cheese, butter, oil, or cream to foods you are preparing or use calorie-enriched milk drinks instead of whole milk. These and other ideas to increase the caloric density of beverages and foods are provided in the table (table 1).

During catch-up growth, the amount of calories and protein that a child eats is more important than the variety of foods eaten. For example, if your child is willing to eat chicken nuggets and pizza but refuses all vegetables, this is usually okay. However, keep trying to offer vegetables and other new foods to help them learn to eat a wider variety of foods. Introduce new foods one at a time to your child's diet as a precaution to identify any food allergies.

At meal and snack time, offer solid foods before liquids.

●Timing of meals and snacks – Try to give your child three meals and two to three snacks on a consistent schedule. The goal is for them to eat approximately every two to three hours but not constantly ("grazing"). Offer the snacks at least an hour before the next meal so they will not spoil your child's appetite for the meal. Also, if your child does not eat their meal, don't offer a snack immediately after; otherwise, they may intentionally avoid eating the meal so that they can have the snack instead. Examples of healthy snacks include crackers, peanut butter, cheese, hard boiled eggs, pudding, yogurt, and fresh fruit or vegetables.

●Specific foods

•Drinks – For most children, whole (full-fat) cow's milk should be their main beverage but no more than 2 to 3 cups (480 to 720 mL) each day. You can give them water or a small amount of fruit juice, but limit to 4 ounces (120 mL) of unsweetened 100 percent juice per day.

•Yogurt – If you want to give your child yogurt, choose a type that is high in calories, protein, and calcium. Try to find a whole-milk (full-fat) yogurt because this will provide more calories compared with low-fat or nonfat yogurts. A variety of yogurt products are available, and the nutrient profiles vary widely, so check the nutrition label. Greek yogurt is a good choice because it may contain up to twice as much protein and calories as regular yogurt.

•Plant-based "milks" – If your child is older than one year, you can choose a nondairy plant-based "milk" alternative if they have a true allergy or intolerance (such as milk protein allergy) or for personal family dietary preferences (vegan diet). For most children, the best choice is a soy-based milk because soy has a more nutritious type of protein than other plant-based milks. Other plant-based milks (such as those made from oat, almond, rice, coconut, or mixed grains) are generally lower in protein and/or have a less "complete" type of protein. Many brands of plant-based milks also contain low amounts of vitamins and minerals. Therefore, it's important to choose a product that is fortified with calcium and vitamin D. If your child drinks one of these other plant-based milks, you will need to work closely with a dietitian to make sure that they eat other foods to provide the nutrients that are missing from the alternative milk.

Eating environment — You might be able to help your child by making changes to the location and atmosphere of where they eat. Tips on food choices, timing of meals, and approach to feeding are outlined in the table (table 2). Include other caregivers and members of your household in the planning so everyone follows the same routine.

●Seating – Position your child so that they are upright and comfortable. Allow them to feed themselves as they are able (eg, by holding a bottle or eating finger foods). Give them plenty of time to work on feeding themselves. For some younger children, you may need to help with spoon feeding. Expect a certain amount of messiness as the child learns to feed themselves. Let them finish eating before cleaning up.

●Surroundings – Minimize mealtime distractions, such as television, videos, phone calls, and loud music.

●Routines – Make mealtime routines consistent, no matter who feeds the child. This includes the location and the way that you offer food.

●Atmosphere – Make the mealtime relaxed and social. When possible, have your child eat with you or other family members, with pleasant conversation (not related to how much the child eats). When your child eats with you and other family members, they can watch how others make food choices and this can encourage them to try new foods.

●Resistance – Do not be discouraged if your child refuses a new food. You may need to offer a new food multiple times (even up to 10 or more) before your child is willing to try it. If they have unusually rigid behaviors (which are common in children with autism), you may need to offer a new food up to 30 times.

●Parent/caregiver responses – To help your child have a positive attitude toward food and eating, you can:

•Encourage, but do not force, your child to eat.

•Praise your child when they eat well, but do not punish them when they do not.

•Avoid withholding food as a punishment or offering food as a reward.

•Set a good example. Model the behaviors you expect your child to have. This may include positive talk about foods/meals and eating a variety of foods.

Medical treatment — If your child has an underlying medical problem that is limiting weight gain, the solution depends on the medical problem. Depending on the problem, you can get advice from your child's primary care provider or from a specialist (eg, an allergist/immunologist for a child with food allergies, a gastroenterologist for a child with an intestine or liver problem, a dietitian for nutritional guidance). Do not eliminate foods and groups of food (eg, milk products) without the advice of a knowledgeable health care clinician, because this can further increase your child's risk of undernutrition. In some cases, the specialist might prescribe a specific treatment, such as a medicine to increase your child's appetite, a special formula to drink, or tube feedings.

If your child is very undernourished, they are likely to be more susceptible to common infections compared with other children. It's a good idea to use normal infection prevention techniques, such as handwashing and avoiding exposure to sick friends or family. However, it's usually okay to let them attend childcare or school. Your child should get all of their routine childhood vaccinations to keep them healthy, like any other child. (See "Patient education: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)" and "Patient education: Vaccines for children age 7 to 18 years (Beyond the Basics)".)

Developmental and behavioral treatment — Developmental and behavioral problems can increase a child's risk of being underweight. For example, children who have difficulty chewing or swallowing food may not be able to consume an adequate amount of food, which, in the long run, can cause undernutrition. Sometimes, medications, such as a stimulant for attention deficit hyperactivity disorder, may decrease their appetite while on the medication. When off of the medication, they may be distracted and have difficulty focusing on the meal.

Early intervention is important, with programs able to provide developmental stimulation, plus physical and occupational therapy when needed. These therapies can help address specific feeding issues. Some children also benefit from seeing a specialty feeding team, developmental-behavioral pediatrician, or behavioral psychologist. These clinicians have specialized training in the medical, psychologic, and social aspects of childhood developmental and behavioral problems.

Psychosocial issues — For some children, slow weight gain is related to issues at home, including:

●Not having access to enough healthy food, due to cost or other barriers.

●The parent or caregiver has a medical or mental health problem (such as depression or alcohol/drug use disorder) or other overwhelming responsibilities (such as work or other caregiving responsibilities) that interfere with their care for the child.

●The parent or caregiver avoids feeding the child certain types of food because they have concerns about health effects (which might not be warranted).

In these situations, the care team can help to improve conditions at home, ensure that there is enough food for all family members, and give tips about healthy eating for the whole family. This may include:

●Home visits by a nurse, social worker, or other clinician to provide education, support, and guidance to caregivers.

●Referral to programs that provide supplemental food, eg, Commodity Supplemental Food Program (www.fns.usda.gov/csfp/commodity-supplemental-food-program); Supplemental Nutrition for Women, Infants, and Children (www.fns.usda.gov/wic); and food stamps (www.ssa.gov/pubs/EN-05-10101.pdf).

●Referral to programs for parents and caregivers, including assistance locating childcare, housing, job training, or treatment for an alcohol/drug use disorder. A social worker can usually help connect a family with these programs.

FOLLOW-UP — 

If your child has slow weight gain, they will need continued follow-up to check on their progress, provide you support, and adjust the treatment plan if needed. The follow-up can be done with your child's primary health care provider or with a specialist. The frequency of visits (weekly to monthly) depends on the individual situation.

During these visits, the health care team will check your child's weight and height and plot the results on a growth chart to see the trend. The clinician will ask you about the child's progress with eating and nutrition and whether you have any new or ongoing questions or concerns. These frequent visits are usually continued until your child's weight gain is steadily increasing and catching up to the typical range for weight gain. If your child can take in an adequate amount of calories, they will usually have catch-up weight gain within three to six months.

You might wonder how your child's period of slow weight gain will affect their height and weight as an adult. The answer depends on several factors, including genetics, the age at which your child was underweight (eg, as young infant, toddler, older child), the severity and duration of the malnutrition, the presence of underlying medical problems, and whether the treatment was able to restore their weight gain and address related medical problems.

WHERE TO GET MORE INFORMATION — 

Your child's health care clinician is the best source of information for questions and concerns related to your child's medical problem.

This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients and caregivers, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Slow weight gain in babies and children (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Pumping breast milk (Beyond the Basics)
Patient education: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)
Patient education: Vaccines for children age 7 to 18 years (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Poor weight gain in children younger than two years in resource-abundant settings: Etiology and evaluation
Poor weight gain in children younger than two years in resource-abundant settings: Management
Poor weight gain in children older than two years in resource-abundant settings

The following organizations also provide reliable health information.

●National Library of Medicine

(www.medlineplus.gov/ency/article/000991.htm, available in Spanish)

●Nemours Foundation

(www.kidshealth.org/en/parents/failure-thrive.html, available in Spanish)

●Academy of Nutrition and Dietetics

(www.eatright.org/for-kids)

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ACKNOWLEDGMENT — 

The UpToDate editorial staff acknowledges Rebecca Kirkland, MD, MPH, and Kathleen J Motil, MD, PhD, who contributed to earlier versions of this topic review.