BTW, 1200 calories in 24 pounds (50 calories per pound)? You'd have to make an effort to go that low. If you have 24 oz bottles and do 1 scoop of Heed per bottle, that's 67 calories per pound. With smaller bottles or more than one scoop per bottle, you get to 100+ calories/pound easy.
I had about 1000 calories of gels, 1200 calories of powders and one small sandwich in 10.5 hours and did 4500 kJ of work.