Many people assume that picky eaters are simply unwilling to try new foods. But picky eating can be more complicated than just social resistance, experts say, and it may be connected to mental health issues.

Certain picky eating habits can be a sign of avoidant/restrictive food intake disorder, or ARFID, in which people "substantially restrict their food intake and experience significant associated physiological or psychosocial problems," according to the latest Diagnostic and Statistical Manual of Mental Disorders, commonly called the DSM-5.

Most people cycle through a menu every eight to 12 days. But people with severe picky eating habits may have a particularly small menu cycle and eat the same thing every day.

That's the conclusion of Dr. Ovidio Bermudez, Eating Recovery Center's chief clinical officer and medical director of child and adolescent services and a spokesperson for the National Eating Disorders Association. He spoke with ATTN: over the phone:

"Most of us end up eating about the same thing every 10 days. For some people, that menu cycle is shorter, so they have a smaller repertoire of things. That person who is a little pickier kind of eats the same thing. There are some people who just eat a lot of different things and enjoy variety, and their menu cycle may be longer, maybe 14 things. If you're so picky that your menu cycle shortens and you're eating the same thing every two to three days, that becomes a problem. Again, if your friends are not like that, it's hard to connect around food with your friends. If your spouse is not like that, it's hard to connect around that. Certainly, if the menu cycle is so narrow that you're eating the same thing every day, then that is clearly outside the norm. That is very extreme pickiness that I think ... would probably fit into the eating pathology sort of spectrum."

It's important to distinguish between avoidant eating patterns — which are more fear-based — and restrictive eating patterns — which represent a lack of interest in certain foods, as opposed to a fear of them, Dr. Bermudez said:

"The people who become afraid of choking and vomiting, that's more anxiety fear-based. That's probably a different type of brain. The people that become restrictive, it's not about the textures or fear of anything; they're just [un]interested in food to the point of not nourishing themselves and having both medical and psychological consequences. I think that's driven by another type of functioning brain, which is clear and distinct."

Non-picky eaters may struggle to understand or sympathize with those suffering from ARFID or who have issues with food.

Such people believe that picky eaters can change the way they eat if they really want to. There is also a lot of judgment surrounding uncompromising eaters. Ordering a food item commonly associated with the kids menu as an adult usually leads to odds stares from others, and failing to eat everything on one's plate is often seen as ungrateful. But people with severe picky eating habits don't have them to inconvenience others, though they inevitably do in social situations.

Los Angeles writer Kayleigh Roberts described in Extra Crispy the struggles of social gatherings for people with ARFID. Roberts said that she has a "mental block against trying new foods or eating certain things based on seemingly arbitrary factors like smell or texture." Because she enjoys breakfast food, it is always a relief to her when people suggest going out for brunch rather than lunch or dinner, where the options of what she can eat are more limited:

"I eat a lot of cereal, oatmeal, and fruit when I’m feeling 'healthy' and a lot of grilled cheese sandwiches and pizza when I'm not. I don't really know what causes it, but it's a constant presence in my life. Any time someone invites me to lunch or dinner, I have to ask in advance what restaurant they want to go to, and then check the menu online to see if there's anything there I can eat. But when someone invites me to breakfast or brunch, I don't have to do that."

People with ARFID may also experience strained romantic relationships because of the way they eat, Dr. Bermudez said. Their children may develop these fears as well:

"I think that marriages suffer. Significant others [too]. It's not just about going out with a bunch of friends. Imagine being married to somebody, and you love restaurants, and you never can make it to a restaurant. And then the other layer is, I think it clearly affects kids. You grow up with a parent who is highly limited in their intake, depending on the temperament of that child, they may internalize that. If that child's genetic makeup is such that they inherited more vulnerability factors, that may be one of the triggering experiences or events they may internalize as, 'Food is risky. Food is dangerous. Food is difficult. Food is not something that I easily endorse.' And that may set the stage for the development of an ARFID-like presentation in themselves or an anorexia-like presentation."

There are those who believe that particularly picky eaters are supertasters by nature, Roberts wrote.

"Supertasters in general get everything more intense," Linda Bartoshuk, a professor who has researched supertasting, told The Wall Street Journal. "When you put it all together, we say that supertasters live in a neon food world, compared to the pastel food world [of non-supertasters]."

About 25 percent of people across the globe fall into the category of supertasters, according to the Journal. Supertasters face social shaming for having rigid dietary preferences. They also have higher odds of developing colon cancer, which the Journal suggested could be the result of eschewing vegetables.

Treating ARFID and similar food issues.

"Like with other eating disorders, early recognition and timely and effective intervention is very important," Dr. Bermudez said. "Timely and effective [treatment] is important, because sometimes these things get recognized, but people go into sort of non-evidence based approaches to deal with these things. I think it's important to find professional help that comes from an evidence-based perspective. At eating recovery center, we work with ARFID patients, both children and adults, both male and female. ... We know best practices, and we know best approaches."

People with ARFID and other eating disorders should seek information online through NEDA, Dr. Bermudez said. He advised against reading blogs or sites that encourage their disorder, such as those of the pro-anorexia community:

"For example, the website of the NEDA clearly has literature-based reliable information about this because there is so much on the internet, and if you search long enough, you can can find anything you want to hear, so to speak. So I think it's really important to advise that as related to ARFID or anything related to eating pathology to be careful, because there are some pro-anorexia and pro-bulimia websites out there whose intention is to teach you to do the bad stuff, do the wrong stuff, to really well-intentioned recovery-oriented websites that really mean to say, 'Don't do this stuff, this is wrong for you.' However, for some people, as they read about things like this, it's an indirect way of teaching them the wrong thing. I think consumers need to be really discerning as to the information that they access and the reliability of that information."

If you are suffering from an eating disorder, you can call the NEDA confidential helpline at (800) 931-2237.