I dont understand Japanese but I'm asian and I can get the overall gist of it.
Basically, the episode is about chubby Japanese idols, and they invited a bunch of them. There's the noributter (butter seaweed) girl named usa maria, the chubby girl idol group and tama mizuki (the one who lost weight).
The audience is largely stunned by how usa maria literally eats butter wrapped in seaweed, the girl idol group introduces themselves and talk about their favourite foods and get laughed at etc, and tama mizuki talks about her weight loss.
For those interested, that chubby idol group can be found on youtube too