Kids who aren't gaining weight: Making sure they're healthy

While we are often faced with the issues of obesity and all the problems it can cause, a number of kids come to see pediatric gastroenterologists and endocrinologists because they need to gain weight.  

They might have problems with 

• Digestion or absorption problems
• Loss of appetite
• Difficulty eating enough
• Illnesses that interfere with their appetite 
• Illnesses that consume their calories 

Sometimes, it's obvious. Other times, looking at their growth charts and BMI shows that even though they're gaining, their weight isn't keeping up with their height growth. 

First, it's important that you and your doctor agree that your child isn't gaining enough. You or your spouse may be on the small side or have had a similar problem as a child. It's important to take that into account. The growth chart though will tell you whether your child is gaining along that same pattern, or is having even more of a struggle than you did. If he or she is, blood tests and stool tests for absorption and specific problems may reveal the cause or at least demonstrate the problem. 

A Careful History and Physical

Your primary care doctor and any specialist you see will often take a detailed history reviewing

• All the symptoms. What's tried and what's been tested
• How long the problem has been going on and whether it's getting worse
• Whether your child has had other problems, including while he or she was in the womb
• The child's diet and any exclusions, texture or behavior issues
• Your family's medical problems

A physical will also be done to look for any abnormalities that could go along with the problem or have resulted from the problem, including any signs of dehydration, malnutrition or any other illness.

The Blood Tests

• Complete Blood Count looks at the hemoglobin and hematocrit, which tells whether your child is anemic, and has normal white blood cells
• Metabolic Panel evaluates the salts or electrolytes (sodium, potassium, chloride and bicarbonate), sugar and calcium levels, the kidney, and usually the proteins (globulins and albumin) and the liver
• Celiac Panel looks at antibodies to gluten and often one of the immune proteins to make sure the antibody level is meaningful. Numerous tests may be included for various reasons
• Thyroid studies evaluate the thyroid in different ways
• Additional studies may look at
• Different protein fractions (pre-albumin)
• Other immune factors (gamma globulin)
• Genetic tests may look for specific conditions, particularly if your doctor suspects an abnormality 
• Growth Hormone (certain ones are ordered at different ages)
• Vitamin levels (especially Vitamin D—the 25-OH version). Vitamin B12 and folate may indicate a great deal about how the water soluble vitamins are absorbed, while Vitamin A or carotene will indicate how the fat soluble vitamins are absorbed.
• Iron studies will help look further at the amount of iron in the diet and iron absorption. 
• Minerals like magnesium and phosphorus may be looked at. If diarrhea is present, zinc may be lost. 

Stool Tests

• Stool for fat will be an important measure of digestion and absorption.
• Stool pH and reducing sugars tell us how sugars are absorbed
• Stool elastase and trypsin indicate if the pancreatic enzymes are adequate and functioning
• Stool alpha-1-antitrypsin checks for any protein loss
• Stool guaiac or globulin looks for blood loss

Those Tests May Point to Others

• Sweat test and genetic studies are done to evaluate for cystic fibrosis
• Endoscopy with biopsies looks at the esophagus and stomach to look for reasons for refusing food; the first part of the small intestine is usually biopsied to look for celiac disease and allergies. 
• Pancreatic stimulation studies may be done to look further at the pancreatic enzymes
• Xrays may be done to look at bone growth or the bone structure. 

Tests That Usually Don't Help

• Allergy testing usually is not helpful
• Colonoscopy is not needed usually unless blood, diarrhea or abnormal lab tests are present
• Other x-rays aren't very useful unless pain, diarrhea or a swallowing problem is also present

Clinical Trials

Sometimes the doctor or dietitian will recommend some dietary changes while the tests are pending or once they're back to see if that dietary trial makes a difference

• A vitamin or mineral supplement may be suggested. 
• An appetite stimulant, most often a mild bendryl-like medicine cyproheptadine (Periactin) or zinc, may be tried 
• And often the best way to tell if these are effective is to look at the diet and weight, before they're started and maybe a month or so afterwards