I'm on my 3rd day of liquid diet,I have very bad headaches any tips?

Drink a ton of Water it MUST be over 8 cups I have like a gallon a day no exxageration on some days (just always have a big water bottle at my desk). Limit caffeine to two cups so you don't dehydrate.

Your not eating any carbs I assume? It can be that too - my headache started around day 3 to 4, for two days, then went away now I am on day 7. I think because your body doesn't have anything to burn and its supposed to burn the fat.

I had horrible caffine headaches because I used to drink a ton of coffee and tea. If you used to drink a lot of caffine this may be causing the headaches. For me they went away in about 4 days. They were horrible!