How is Failure to Thrive Different from Malnourishment?

Courtesy of Godoy Medical Forensics


When you think of malnourishment and failure to thrive, your first thought is not of children in developed countries, such as the United States. When it is seen in the United States, it is usually a result of a medical condition that prevents the body from utilizing the nutrients being provided. The incidence of failure to thrive relating to intentional child neglect is not well studied, but fewer than one percent of children in the United States have chronic malnutrition (Sirotnak, 2013).

The World Health Organization (WHO) defines malnutrition as “the cellular imbalance between supply of nutrients and energy and the body’s demand for them to ensure growth, maintenance, and specific functions” (Shashidhar, 2013). Failure to Thrive is a more quantitative definition where “the diagnosis is based on growth parameters that (1) fall over 2 or more percentiles, (2) are persistently below the third or fifth percentiles, or (3) are less than the 80th percentile of median weight for height measurement. Growth failure is now generally accepted to be overly simplistic and obsolete.” That last sentence indicates that the previously used term “Growth Failure” is not accepted as a diagnosis in any case, and that children do not simply stop growing.

The American Academy of Pediatrics (AAP) has another criteria of “significantly prolonged cessation of appropriate weight gain compared with recognized norms for age and gender after having achieved a stable pattern” (Block, Krebs, Committee on Child Abuse & Neglect, & Committee on Nutrition, 2005).

Symptoms of Malnourishment

When a child is malnourished, the initial symptoms will be simple weight loss or stagnancy of weight gain. A child may demonstrate more severe symptoms—such as seizures related to low blood sugar or electrolyte imbalances—when the malnutrition is severe or prolonged. A child with underlying conditions may demonstrate these symptoms with even mild malnutrition or in acute circumstances, making it difficult to determine the true cause.

Severe cases that are prolonged will cause significant delays in development, as well as psychological scarring. An example is the recent case in Denver from October of 2013 where 4 children ages two to six were found unable to speak and their ages were difficult to determine due to severe and prolonged abuse and neglect. This case was the extreme and not what you will commonly see, even in the criminal courts.

The cases that we have reviewed at Godoy Medical Forensics have been much more subtle, where a diagnosis was made after several months or even years of assessment and care by the healthcare providers. Underlying conditions—such as Down Syndrome and other genetic disorders, endocrine disorders, and blood disorders—complicate the analysis of these cases. Underlying conditions like these make it difficult to determine if the child is also being intentionally malnourished on top of their disorder—affecting the body’s ability to metabolize nutrients. In each case, the child had difficulty gaining weight and demonstrated the symptoms thought to be from withholding food, even while hospitalized.

Diagnosing Failure to Thrive

Weight alone is not the sole factor in diagnosing failure to thrive. As the definitions in this blog post indicate, it is “growth parameters” that are recorded, not just the weight. It is the weight-to-height ratios, body mass index (BMI), and z-scores that should be evaluated when considering a diagnosis of failure to thrive. Weight-to-height is considered to be normal if the percentage is between 5 and 85 percent. BMI values are normal between 18.5 and 25. Both of these are relatively well-known or understood, even in non-medical communities. Z-scores are a calculation of the child’s standard deviations from the norm—with normal being zero—and are generally used when the child falls into the extremes (less than 3 percent or more than 97 percent) of the weight to height percentiles, as they are a more precise calculation of the child’s growth and weight gain. Therefore, z-scores are not as well known and are not used as often, except in severe cases of failure to thrive.

There are also certain conditions, such as Down Syndrome, that have their own growth charts because these children do not plot correctly on the standard growth charts. In the example of Down Syndrome, they are considered normal between -2 and -3 standard deviations, or a z-score of between -2 and -3. Clearly, this would have an affect on the assessment of failure to thrive.

Mimics for Failure to Thrive


  • Parents incorrectly preparing formula or feeding solution:
    • Formula is expensive and financial restraints or lack of education may lead the parents to dilute the formula.
  • GERD (Gastroesophageal Reflux Disease):
    • Symptoms: spitting up, vomiting, coughing, irritability, poor feeding, blood in the stool (National Institute of Health, 2006).

Medical causes:

  • Cystic Fibrosis;
  • Down Syndrome;
  • Brain damage;
  • Heart or lung problems;
  • Anemia and other blood disorders;
  • Gastrointestinal problems;
  • Cerebral palsy;
  • Chronic infections;
  • Metabolic disorders;
  • Complications of pregnancy and low birth weight.