Sugary cereals for breakfast, a protein bar as a snack, a microwave lasagna for lunch, and a frozen pizza for dinner sounds like a teenager's dream diet, but these are the types of foods physician Chris van Tulleken ate for four weeks. During this time, he got 80 percent of his daily calories from ultra-processed foods, to see how it would impact his health and mood. He writes about this experience, and his extensive research on these products in his new book, "Ultra-Processed People: The Science Behind Food That Isn't Food." Host Maiken Scott talks to Van Tulleken about the link to obesity and disease, and why he says we should probably avoid anything that's marketed as a health food.