Does blotting my slice of pizza with a napkin actually save calories?

It sure does. Every quarter-tablespoon of oil that drips off your slice contains between 20–40 calories, which can add up. Data shows that the average person eats 6,000 slices of pizza in a lifetime. Let’s exclude the hundreds or so you’ve probably already eaten. Assuming you blot 30 calories of oil off each slice, you’ll save 150,000 calories; divide that by 3,500 (the number of calories in a pound), and you save more than 42 lbs in a lifetime.