Calories aren't bad for everyone.

Consuming more calories than you're expending causes you to gain weight, and for most (but not all) people that's probably bad for you. I often supplement small meals with large amounts of nuts and it's the calories - in the form of fats, including many heart-protective fats - that I'm after.

I believe I'm better off getting those 2,000 calories from nuts than from, say, meat or refined sugar. But obviously everyone's bodies and personal health situations vary.