Diet soda is a hoax, and makes you gain weight
That's a subjective statement. Consider this: what majority of people are drinking diet drinks? Overweight people, usually. Sometimes, subconsciously, drinking a zero calorie artificially-sweetened drink can give a sense of wanting to eat more due to consuming less calories through liquids. It really is a possibility.
As for diet soda causing weight gain? Hogwash. A caloric surplus will heed a gain in weight just as a caloric deficit (consistently, over time) will heed a loss of weight.
As for body composition and all things related, that can be debated, but I feel that this is not the appropriate time to do that. 90% of the nutritional information that's spewed all over the internet is nothing but mindless drivel created behind the motivation and incentive of the holy dollar: money. I'd rather take into account PubMed or peer reviewed science journals that weigh every thought. The diet soda craze and the saturated fat backlashes are two things that grind my gears.
"Diet soda is a hoax, and makes you gain weight" -- consider wording your posts differently. Look up 'post hoc ergo propter hoc'. Correlation does not always equal causation.
Hopefully my post didn't sound too vitriolic or worthy of being noted as attacking, as tone and a proper voice on the internet does not allow a person to write with their actual intentions when it's interpreted by the other person.