actually, adding large amounts of lemon juice to a galllon of water can be very beneficial if you are pre-contest dieting. lemon juice has duiretic qualities and can be used in conjuction with dandilion root to rid the skin of excess water.(alot safer than using laxis or harsh diuretics like that) i must warn you, be prepared to pee like a mother. this is what i do:
for every one gallon of water, i dump a 1/4 cup of lemon juice.
if you buy the lemon juice concentrate in a bottle, it has next to zero carbs.