FAO has been compiling a cross-country annual panel data on per capita calorie availability.
FAO (2001)'s Food Balance Sheets: A Handbook describes how the data is constructed.
The data can be downloaded at a FAOSTAT webpage. (Uncheck FBS Style and select Grand Total+ in the list of item.) All the disaggregated data is also downloadable.
Used by Lisa Blaydes and Mark Andreas Kayser's working paper entitled "Counting Calories: Democracy and Distribution in the Developing World".
The calorie availability data used in pages 8-9 of Pritchett (1997) (to gauge the subsistence level of GDP per capita) and in Deaton (2007) (to investigate the determinants of human height) is presumably the same data.