There's been a cultural fixation on a high-protein diet for years — and experts say we might be taking it too far. In a tweet shared on Thursday , Health and Human Services Secretary Robert F. Kennedy Jr. honored what he considers an important moment of celebration for the country: National Burger Day. “It’s #NationalBurgerDay,” Kennedy posted on X, along with a photo of him flipping raw meat patties on a kitchen grill. “The war on protein is over, and REAL American beef is back on the menu.”