macro?

Foods have nutrients in them and the proteins, carbohydrates and fats found in foods are called macronutrients and the vitamins and minerals found in those same foods are called micronutrients. Some foods have more micronutrients in them as it relates to it's calorie content and those foods are referred to as nutrient dense and conversely when a food has fewer nutrients the food is considered calorie dense or calorific.

Well, when devising a diet the food you include in that diet will be broken down into macro's showing what percentages of each macro your consuming. For example protein and fat as essential nutrients and must be consumed in minimal quantities for good health and Carbs are generally consumed to meet specific lifestyle needs or preference. Basic explanation.