It may Depend Greatly if the Watermelon is Good or Not for one to eat, by how it was raised !
One may Determine this by the use of a Refractometer, and if it is of a Low Brix, then it may not be worth eating, especially if it is also showing a sharp line, which may indicate it has NPN in it !
And if it has NPN, then it may be Potassium Nitrate, and too much of Potassium Nitrate may "KILL" a person by "STOPPING" the Blood from being able to carry Oxygen !
How long can "YOU" Live without Oxygen ?
So, it may be Better to not make Flat Claims that certain foods are Good, without considering their Quality or Lack of Quality First !