What they're saying: "We've seen a gradual trade up among dairy milk consumers, from fat free to skim, and skim to reduced fat, and reduced fat to whole fat," Chris Costagli, VP of food insights for the marketing research firm NIQ and a dairy industry veteran, told Axios.

• "Consumers have started to embrace healthy fat. Not donuts and ice cream, but natural fat," he said.

By the numbers: Whole milk increased 7.2% in sales compared to last year, according to NIQ data shared with Axios.

Between the lines: Whole milk is recommended for children 1 to 2 years old — but for everyone else, the "right" milk depends on individual health, genetics and overall diet, says dietitian Tamara Duker Freuman.

• If you have high cholesterol, or you already consume saturated fats in other foods as part of 10% of your daily calorie intake, "you are better off choosing lower-fat or fat-free milk," Freuman said.
• But if not, and a daily whole milk latte is "literally the only regular source of saturated fat in your otherwise healthy diet," she said, "then enjoy it."

The latest: Some new infant formulas from startups Bobbie and ByHeart are made with whole milk instead of the industry-standard skim milk.

• Whole milk retains cholesterol, natural milk fat and the way the fat is carried in the milk (the milk fat globule membrane, MFGM) — all of which are present in breast milk and play a role in infant brain development and hormone production, said Sharon Donovan, professor of nutrition at the University of Illinois, Urbana-Champaign.
• Most traditional formulas strip out these components and then add oils and isolated proteins to try to rebuild them, Donovan — who's an adviser on the scientific board for ByHeart — told Axios.

What we're watching: Whether whole milk will return to school cafeterias and if formula changes as Health and Human Services Secretary Robert F. Kennedy Jr. launches Operation Stork Speed.