system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What do alcohol "empty calories" mean exactly? How come something has calories but no carbohydrates, protein or fat?
gpt
"Empty calories" refers to foods that provide calories but little nutritional value such as vitamins, minerals, fiber and protein. Basically it makes you fat without properly nourishing you.

For your 2nd question: alcohol itself has calories.