Health Secretary Robert F. Kennedy Jr. has directed the Food and Drug Administration to review the nutrients and other ingredients in infant formula, which fills the bottles of millions of American babies. The effort, dubbed “Operation Stork Speed,” is the first deep look at the ingredients since 1998.

“The FDA will use all resources and authorities at its disposal to make sure infant formula products are safe and wholesome for the families and children who rely on them,” Kennedy said.

About three-quarters of U.S. infants consume formula during the first six months of life, with about 40% receiving it as their only source of nutrition, according to the Centers for Disease Control and Prevention.

Formula has been widely used in the U.S. for roughly six decades, feeding generations of infants who have flourished, said Dr. Steven Abrams, a University of Texas infant nutrition expert.

The broader scientific community has been calling for a reevaluation of infant formula for years and is “fully supportive of this idea of a comprehensive look,” he said.

Current formula products in the U.S. continue to be safe and nourishing, he said.

“But there’s been a lot of science and we want the FDA rules to align with the most recent science from around the world,” he said.

Here’s what you need to know about Operation Stork Speed.

What is infant formula and why do so many babies consume it?

Infant formula is a manufactured product, usually made from cow’s milk or soy, that is intended to mimic human breast milk for kids up age 12 months. It may be the sole source of nutrition or supplement breastfeeding.

FDA regulations require that infant formulas contain 30 specific nutrients, with minimum levels for all and maximum levels for 10 of them.

The ingredients vary, but all formulas must have a balance of calories from protein, carbohydrates and fat that mirrors what’s found in human milk.

Federal guidelines recommend that babies be exclusively breastfed for the first six months of life and that parents continue breastfeeding for the first year or more while adding new foods to the child’s diet.

Parents use formula when a mother cannot or chooses not to breastfeed for a wide range of reasons, including medical conditions, work conflicts, to allow other family members to help with feedings and other situations.

Why is the government reviewing baby formula now?

Kennedy announced the review of infant formula in March as part of his “Make America Healthy Again” agenda for the U.S. food supply.

The FDA’s review will include increased testing for heavy metals and other contaminants as well as a review of nutrients, the agencies said.

U.S. health officials will hold a two-hour roundtable discussion of infant formula on Wednesday.

What issues will that cover?

The FDA is asking for new scientific data and information about whether required ingredients in infant formula should be added, removed or changed. The deadline for comments is Sept. 11.

Scientists say a review is long overdue regarding the most recent data on the composition of human milk and how babies digest and absorb nutrients in breastmilk and formula.

In addition, they want the FDA to consider how U.S. formulas compare with those made elsewhere, said Bridget Young, who studies infant nutrition at the University of Rochester.

“How do our regulations differ?” she said. “Maybe it’s time for them to relook at their regulations and consider potential international harmonization.”

More international alignment might have eased the U.S. infant formula crisis in 2022, when contamination shut down an Abbott factory, leading to monthslong shortages for American parents, Young said.

What about specific ingredients?

In recent years, some parents have sought out infant formula made in Europe with the belief that products made overseas are healthier options, experts said.

Formula regulations in the U.S. and Europe, including requirements for nutrients and testing, differ somewhat, but are generally similar, Abrams said.

“The differences between the U.S. and Europe should not be considered as ‘higher’ or ‘better’ or ‘greater’ in one vs. the other,” he said.

Still, iron, for instance, is included at higher levels in U.S. formulas than in those in Europe — and Abrams suggested that U.S. officials may consider lowering iron targets.

Other components have been added to formula in recent years. They include docosahexaenoic acid, or DHA, an essential omega-3 fatty acid, and human milk oligosaccharides, complex sugars that are found breast milk but not in cow’s milk. Although they may be beneficial, they are not required.

“These have been added to some formulas, but not to other formulas, so we want to take a look,” Abrams explained.

Many parents have raised concerns over formula ingredients such as added sugars and seed oils, which are also being targeted by Kennedy as hazards in the wider food supply.

Recent research suggests that added sugars such as glucose and corn syrup solids in infant formula may be linked to weight gain in children. Young said that most experts agree that lactose, the primary type of sugar found in breast milk, is preferred.

Infant formulas in the U.S. do contain seed oils, Young said. But that’s because there are a finite number of vegetable oils that provide the essential saturated and unsaturated fats that babies require.

“They need to provide the variety of fatty acids that you see in breast milk,” she said.

What are the next steps?

Done properly, the FDA’s infant formula review would take “at least a year,” Abrams said. And it will require broad input from multiple government agencies, formula manufacturers and consumers.

“No shortcuts are possible and no one review, white paper or even committee report will suffice to do it right,” he said.