How many calories does it take to raise 1 kg 1 meter?

The work done is transformed into potential energy (in the object lifted) so

W = m x g x dz where

W = Work

m = mass

g = acceleration due to gravity

dz = change in height

=> W = 1kg x 1m x 9.81m/s/s

=> W = 9.81J

1J = 0.239 calories

=> It takes 2.345 calories to lift 1kg by 1m

NOTE

These are "real" calories. The calories usually talked about in relation to dieting etc are kilo-calories so to equate this value to the calories in a chocolate bar, divide by 1000