Never heard of adaptogens though your suspicions are probably right on target. Liquid diets have been around since at least the 1950’s like Metrecal from Mead Johnson which was mostly powdered skim milk and doesn’t produce lasting weight loss according to research.
Successful weight loss means you keep it off, some researchers say for at least 1 year after you have reached your goal weight. I wonder why not keep the weight off for the rest of your life? Research has proven successful weight loss is accomplished through a slow weight loss using a moderate calorie reduction, exercise 60 minutes 5 times per week and logging everything you eat.