"Our bodies are very good at controlling our blood sugars (as long as we do not have insulin resistance or prediabetes/type 2 diabetes)," explained Spencer Nadolsky, MD, a board-certified family and obesity physician with Renaissance Periodization. He said we don't need to eat every three hours, and we don't need to eat all three macronutrients at once, either.
Dr. Nadolsky said that while some people may do well controlling hunger by eating every three hours, "some may do better with fewer meals when it comes to hunger" because eating that often can actually increase hunger. If eating every three hours helps with your hunger and helps you eat fewer calories, then that's fine. "But some do better by spacing out their meals longer, which is why many people find weight-loss success with intermittent fasting."
As far as eating protein, fats, and carbs at every meal and snack, Dr. Nadolsky said, "Some do better eating only two macronutrient types per meal, either protein and fat or protein and carbs. You don't have to have all three."
There is also the crucial point that everyone is different and has different dietary needs. An athlete who's trying to build muscle will need more protein than a person who's not exercising. A long-distance runner will need more carbs than someone who sits at a desk all day. It's important for each individual to figure out their macronutrient needs, and seeing a registered dietitian can help you figure that out.