To find out how much money Les spent on food, we simply need to subtract the amount of money he had left from the amount he originally had.
Les had $26.00 and after shopping, he had $11.70 left.
So, we calculate the amount spent as follows:
\[ \text{Amount spent} = \text{Original amount} - \text{Amount left} = 26.00 - 11.70 \]
Now, performing the subtraction:
\[ 26.00 - 11.70 = 14.30 \]
Therefore, Les spent $14.30 on food.