Almost every jar of pickles claims a serving of pickles has zero calories. Now clearly, this is incorrect and the result of exploiting some ridiculous FDA loophole, since anyone knows that cucumbers provide calories.
So let’s say you’re in a situation where you lose all access to food, but you’ve got effectively unlimited access to pickles – like, you’re trapped inside a recently abandoned pickle warehouse.
Could you conceivably eat enough pickles to survive for a month? Two months? Or would your body just shut down from all the sodium and acid?
For the water part, in the wikipedia article it is said in context with the claim that people lose 4.5 kg within a week. That weight is unrealistically just fat. A kg of body fat has about 7700 kcal iirc (I remember it is not exactly 9000 kcal/kg but less and google spat out 7700), so that would necessitate an energy expenditure of 3850 kcal/day (if you wanted to lose 4.5 kg/7 days). This would be a lot, at least for a regular sized person with moderate activity levels (mostly we estimate 2000-2500 kcal/day as an energy need). You also have something like 2000 kcal saved in your body as glycogen, which will also be broken down of you fast. Glycogen is stored in a kind of “water shell”, so when you burn through glycogen, you also “lose water” (1 g of glucogen : 3 g of water I think). Considering you’ll put your body in a kind of “fasting mode”, the diet will also cause a metabolic response where your metabolism will slow down and cling on what you have. Muscles will also be broken down for gluconeogenesis from amino acids.