A major pediatricians’ group is urging families to limit the use of plastic food containers, cut down on processed meat during pregnancy and consume more whole fruits and vegetables rather than processed food. Such measures would lower children’s exposures to chemicals in food and food packaging that are tied to health problems such as obesity, the group says.

The American Academy of Pediatrics issued the guidelines in a statement and scientific technical report Monday. The group joins other medical and advocacy groups that have expressed concern about the growing body of scientific evidence indicating that certain chemicals that enter foods may interfere with the body’s natural hormones in ways that may affect long-term growth and development.

The pediatricians’ group, which represents some 67,000 children’s doctors in the country, is also calling for more rigorous testing and regulation of thousands of chemicals used as food additives or indirectly added to foods when they are used in manufacturing or leach from packaging and plastics.

Among the chemicals that raised particular concern are nitrates and nitrites, which are used as preservatives, primarily in meat products; phthalates, which are used to make plastic packaging; and bisphenols, used in the lining of metal cans for canned food products. Also of concern to the pediatricians are perfluoroalkyl chemicals, or PFCs, used in grease-proof paper and packaging, and perchlorates, an anti-static agent used in plastic packaging.

“The good news is there are safe and simple steps people can take right now to limit exposures, and they don’t have to break the bank,” said Dr. Leonardo Trasande, the lead author of the statement and chief of the division of environmental pediatrics at New York University’s School of Medicine.

“Avoiding canned food is a great way to reduce your bisphenol exposure in general, and avoiding packaged and processed food is a good way to avoid phthalates exposures,” Trasande said. He also suggested wrapping foods in wax paper in lieu of plastic wrap.

Jonathan Corley, a spokesman for the American Chemistry Council, a trade association, said: “Chemicals are critical to protecting the quality and integrity of food, help in the safe transportation and storage of food.” He said that many of the chemicals referred to in the AAP statement did not act as endocrine disrupters “in typical uses and at typical exposure levels,” but did not provide scientific references to support that contention.

In a separate development Monday, scientists at the University of California, San Francisco, who used a novel method for scanning blood said they had found dozens of chemicals called environmental organic acids, or EOAs, in pregnant women.

EOAs, which include bisphenol-A, have chemical structures similar to hormones, meaning they may disrupt the endocrine system of the fetus and interfere with development. Researchers involved in the study, published in the journal Environmental Health Perspectives, said some of the chemicals had never before been documented in the blood of pregnant women, including two chemicals that are linked to genetic defects, fetal damage and cancer.

Among the other chemicals detected in the pregnant women were an estrogenic compound used in food-related plastic products, plastic pipes and water bottles, as well as a compound banned for use as a diet drug by the Food and Drug Administration decades ago because of the risks but still used in cosmetics, pesticides and as a coloring agent in industrial processes, said Aolin Wang, one of the study’s authors.

Infants and children are particularly vulnerable to the effects of chemicals in food in part because they eat more food per pound of body weight than adults. Perhaps more significantly, children’s metabolic systems and key organ systems are still developing and maturing, so hormone disruptions can potentially cause lasting changes.

“Because hormones act at low concentrations in our blood, it is not surprising that even low-level exposures to endocrine disrupters can contribute to disease,” said Laura N. Vandenberg, an assistant professor in the department of environmental health sciences at the University of Massachusetts-Amherst’s School of Public Health, who spoke on behalf of the Endocrine Society.

Many of the chemicals described in the pediatrics report have been shown to interfere with normal hormone function “by mimicking or blocking the actions of hormones that are responsible for brain development, development of the sex organs and normal metabolic functions,” she said.

Child obesity in the United States has more than tripled since the 1970s, with nearly one in five children ages 6-19 considered obese; the prevalence of developmental disorders in children increased from the 1990s to the mid-2000s; and rates of diagnoses of both Type 1 and Type 2 diabetes among children and teenagers are also on the rise, according to the Centers for Disease Control and Prevention.

The AAP statement was particularly critical of a regulatory process by which the FDA designates food additives “generally recognized as safe,” citing a 2010 Government Accountability Office review of the program that determined “the FDA is not able to ensure the safety of existing or new additives through this approval mechanism.”

An FDA spokeswoman, Megan McSeveney, said the agency does not comment on specific statements or studies, but said that food safety “is at the core of the agency’s mission to protect and promote public health for our nation’s consumers.”

She said FDA regulations define “safety” for substances in food to mean “there is reasonable scientific certainty that the substance is not harmful when used as intended,” and that applies to food additives, color additives and substances that are generally recognized as safe as well as substances that are used in producing, packing, preparing or processing food that “are expected to become components of food.”

“If new information (such as published studies and adverse event reports) suggests that a substance already in use may be unsafe (whether it is an additive or otherwise exempt), or if consumption levels have changed in ways that could affect safety, the FDA can conduct further studies to review whether the use can still be considered safe,” McSeveney said in an email. The pediatrics group suggests that doctors recommend families take the following steps in order to reduce chemical exposures to children:

— Prioritize the consumption of fresh or frozen fruits and vegetables whenever possible.

— Avoid processed meats, especially during pregnancy.

— Avoid microwaving food or beverages — including infant formula and pumped breast milk — in plastic containers, and do not put plastic food containers in the dishwasher.

— Use alternatives to plastic, like glass or stainless steel, whenever possible.

— Check the recycling code on the bottom of products and avoid plastics with recycling codes 3, 6 and 7, which may contain phthalates, styrene and bisphenols, unless they are labeled “biobased” or “greenware,” indicating they are made from corn and do not contain bisphenols.

— Wash hands before handling food and drinks, and wash all fruits and vegetables that are not peeled.