Hello. I had to drop by and leave a comment. I know one way to find out if one is still attaching to the habit of eating like Ron said, one can eat only one thing everyday for 10 days to see if the craving is still there for other food. Say eating brown rice everyday for example.
Asceticism is contrary to the principle of Vajrayana.
I don't agreed, developing some renunciation is very useful for Vajrayana practice. To say it doesn't work is just plain wrong. Sure renunciation as such is part of Hinayana and Mahayana as classified by Tibetans and Vajrayana is the path of transformation. But if you haven't developed some renunciation first your Vajrayana practice will be somewhat lacking.
Eating one thing only for 10 days is not some form of extreme asceticism. A simple diet of only rice or something similar and not much else is pretty common within Monasteries of all traditions.
Also it is within Vajrayana that you will find the most extreme sorts of asceticism when it comes to diet. The hermits and anyone who does a retreat. Milarepa who lived on nothing but nettle soup, what about feeding from a small rock in your mouth or just air? Also many practices like chulen and others. The intention behind these is of course not renunciation or asceticism of the sake of being ascetic, just to be clear. But newer the less i think your comment was misleading.