As part of a promise to address the high rates of chronic disease in the United States, Robert F. Kennedy Jr. — who was recently tapped by President-elect Donald J. Trump to lead the Department of Health and Human Services — has said that he would “fix our broken food system.”

In interviews and on social media, Mr. Kennedy has made a number of claims about the country’s food supply and eating habits. We fact-checked five of his most repeated refrains.

Ultraprocessed Foods

His claim: Ultraprocessed foods are driving the obesity epidemic, and they should be removed from school lunches.

What the research suggests: Many public health and nutrition experts agree that ultraprocessed foods — which make up an estimated 73 percent of the U.S. food supply — are probably contributing to the obesity crisis in the United States, and it would be beneficial to cut back on them.

But the category is wide-ranging, and it’s not clear if all ultraprocessed foods are harmful, experts say. There may be downsides to avoiding some ultraprocessed foods, like flavored yogurts and whole wheat breads and cereals, they add, because they can provide valuable nutrients.

Lindsey Smith Taillie, an associate professor of nutrition at the U.N.C. Gillings School of Global Public Health, said that it would be “transformative” to remove ultraprocessed foods from school lunches. But, she added, schools would need more resources to prepare meals from scratch.