From the prefix
macro, plus
nutrient. Macronutrients are
chemicals that
animals need to ingest in large quantities to sustain
life and
health.
Carbohydrates,
proteins, and
lipids (
fats) are the major sources of
calories, and are considered macronutrients. They are joined by
water, which must also be consumed. A few oddball substances, like
alcohol also provide calories but are not considered macronutrients because they have no other nutritive properties. Required quantities of macronutrients for humans can be measured in the tens or hundreds of
grams per
day.
Macronutrients are contrasted with
micronutrients, which are required in much smaller amounts.