Click to see a bigger picture. I'm not sure what the soymilk cookies are supposed to reset in one day (appetite?), but I have my doubts about their ability to suppress appetite.
One of the things I remember my mother buying when I was a kid was a box of "diet" candy called Ayds. Setting aside the product name which would now remind people of a terrible disease, this product always seemed to me like a bad concept. The idea with Ayds, as it is with these diet cookies (which are rampant in Japan), is that you eat candy, cookies or bars instead of meals. While they may be packed with chemically distilled vital nutrients, I can't imagine that they fill the space in your stomach very effectively. I should note that, in addition to the plethora of these types of cookies made my Japanese manufacturers, there was also a big push for a much more expensive French-made diet cookie in many stores.
Still, Japanese people seem to be far better at "enduring" (gaman) hardship and deal with these meal substitution plans better than my mom did. The Ayds never helped her lose weight, after all.