2000 calories in Big Macs: $17.87 at a US McDonalds
2000 calories in SlimFast meal replacement shakes: $13.13 at Wal-Mart
2000 calories in SlimFast powder: $8.94 at Wal-Mart
How did you get that?
According to McDonald's own nutritional information [1], you'd consume 1,070 calories per medium meal. Via:
Big Mac: 530 calories
Medium Fries: 340 calories
Medium Drink: 200 Calories
In order for your maths to work each meal has to cost $8.94. The most expensive medium big mac meal I can find is $8.03 in DC, or $16 for your 2K calories.
[0] http://www.fastfoodmenuprices.com/mcdonalds-prices/
[1] http://www.mcdonalds.com/us/en/food/full_menu/full_menu_expl...
I live in a house of 8 where we order food communally, last month my food bill was £93.35 ($145.50), so $4.85/day for three (subjectively very healthy) meals.
Not your typical setup, but still perhaps of interest.