Nutritionists often group nutrients into two subclasses, called macronutrients and micronutrients. Macronutrients refer to those nutrients that form the major portion of your consumption and contribute energy to your diet. Macronutrients include carbohydrates, fats, protein, and alcohol. Sometimes water is also considered to be a macronutrient. All other nutrients are consumed in smaller amounts, and are labelled as micronutrients.