Keto for weightloss is a meme. It is supposed to help reduce seizures epileptic children not help adults loose weight.

Weight Watchers is subscription based weight loss, the primary goal is to keep the dieter feeling like it will take just one more month to reach that goal, but they never will ;)

Paleo is just a huge joke, in span of the Paleolithic era humans went from being field apes to full on farmers. So a true paleo diet could include anything from raw rabbit to a burger on baked bread.