Pica is officially classified as an eating disorder. Specifically, the DSM-5-TR (the standard diagnostic manual used in psychiatry) places it under “Feeding and Eating Disorders” alongside conditions like anorexia, bulimia, and avoidant/restrictive food intake disorder (ARFID). What makes pica distinct from those other eating disorders is that it doesn’t involve restricting, bingeing, or purging normal food. Instead, it involves persistently eating things that aren’t food at all.
What Pica Actually Involves
Pica is the repeated eating of non-nutritive, non-food substances for at least one month. The list of things people with pica eat is surprisingly long: clay, dirt, chalk, paint chips, paper, soap, hair, ice, laundry starch, charcoal, pebbles, eggshells, coffee grounds, and even feces. Some people fixate on a single substance, while others eat several different non-food items.
Not every instance of eating something strange counts as pica. To meet the diagnostic threshold, the behavior has to be developmentally inappropriate. Children under two routinely mouth and swallow objects as part of normal exploration, so pica isn’t diagnosed before age two. The behavior also can’t be part of a recognized cultural or religious tradition, since some communities have long-standing practices of eating certain clays or soils.
Who Is Most Likely to Develop Pica
Pica affects a wider range of people than most realize. About 1.1% of adults and roughly 5% of children ages 7 to 14 experience recurrent pica behaviors. But the rates climb sharply in certain groups.
Pregnant women are one of the most commonly affected populations. A meta-analysis of approximately 70 studies found that nearly 28% of pregnant women worldwide exhibit pica behaviors, with higher rates in developing countries where anemia is more prevalent and access to nutrition education is limited. Craving ice, clay, or starch during pregnancy is far more common than many people expect.
Pica is also significantly more common in people with autism spectrum disorder, intellectual disability, ADHD, schizophrenia, obsessive-compulsive disorder, and depression. Children with heightened sensory sensitivity traits are more likely to eat inedible substances than children without those traits, which helps explain the strong overlap with autism.
Why People Eat Non-Food Items
The causes of pica aren’t fully pinned down, but nutritional deficiency plays a clear role in many cases. Iron deficiency is the most strongly linked factor. Iron deficiency anemia is three times more common in people who eat clay, and there’s a chicken-and-egg quality to the relationship: low iron may drive the craving, but eating clay and starch also blocks iron absorption in the gut, making the deficiency worse. Zinc and potassium deficiencies have also been implicated, since clay’s chemical structure can bind these minerals and prevent the body from absorbing them.
What’s particularly telling is that iron supplementation often stops pica behavior. Researchers have noted that iron therapy accelerates the end of these cravings, even though the cravings tend to resolve on their own over time. This suggests the body may be generating a misguided signal to seek out minerals, leading people toward substances like soil or clay that contain trace amounts of what they’re lacking.
In people with developmental disabilities or mental health conditions, the drivers can be different. Sensory-seeking behavior, difficulty distinguishing edible from inedible items, or compulsive tendencies may all contribute. Stress and neglect have also been associated with pica in children.
Health Risks of Pica
The medical dangers depend heavily on what’s being eaten. Some of the most serious risks include:
- Lead poisoning: Children who eat paint chips or objects coated in lead paint dust are at high risk. Lead levels should be checked whenever this is suspected.
- Intestinal blockages: Non-food materials can clump together in the stomach or intestines, forming a bezoar, a mass of undigestible material that may require surgical removal. Symptoms include belly pain, nausea, and bloating.
- Parasitic infections: Eating contaminated soil or animal feces can introduce parasites and harmful bacteria.
- Nutritional deficiency: Substances like clay and starch interfere with mineral absorption, and filling up on non-food items can displace actual nutrition.
- Dental damage: Chewing on hard materials like pebbles, charcoal, or ice can crack or wear down teeth over time.
There’s also an underappreciated risk of lead and iron deficiency reinforcing each other. Research suggests lead and iron share a common absorption pathway in the gut, so iron-deficient individuals may absorb more lead from the same exposure. A child with pica who is already low in iron and eating paint chips faces a compounded danger.
How Pica Differs From Other Feeding Disorders
The DSM-5-TR contains three feeding disorders that are sometimes confused: pica, rumination disorder, and ARFID. Pica is specifically about eating non-food items. Rumination disorder involves repeatedly regurgitating food, re-chewing it, and either re-swallowing or spitting it out. ARFID is a pattern of severely restricted eating based on sensory aversions, fear of choking, or lack of interest in food, but the person is still eating actual food. All three can occur in children or adults, and it’s possible to have more than one at the same time.
Pica is also distinct from intentionally swallowing objects to cause self-harm or to fake an illness, which falls under a different diagnostic category entirely.
How Pica Is Treated
Treatment typically addresses both the behavior and whatever is driving it. If blood work reveals an iron or zinc deficiency, correcting that deficiency with supplements often reduces or eliminates the cravings. For pregnant women, this can be as straightforward as adjusting prenatal vitamin intake.
When pica is linked to a developmental or psychiatric condition, behavioral interventions become the primary tool. These generally involve redirecting the person away from non-food items, reinforcing appropriate eating, and making the environment safer by removing access to harmful substances. For children with autism or intellectual disability, applied behavior analysis techniques are commonly used.
In cases where someone has already developed complications, like a bezoar or lead poisoning, treating the medical problem takes priority. The outlook is generally good when the underlying cause is identified and addressed, though pica can persist for years in individuals with severe developmental disabilities if ongoing behavioral support isn’t in place.