Maybe I’m missing something (and I want to be clear I’m not picking on this particular user at all!), but it’s not clear how a barfing cat is related to eating less junk food. The two interpretations I could see are “I was so distracted I forgot to enter data, but I didn’t eat any junk food either” OR “I was so frazzled, I couldn’t get dinner made and had to order out.” Those are very different situations!
In my mind, simple “I forgot to enter data” cases don’t need much prodding, beyond perhaps making sure the person is aware of the options for variable deadlines, reminder settings, etc. Nearly all of my non-legit derails are some variation of “I forgot”, and if anything it’s become more likely to happen as my new habits get better established.
The second case is something a bit different, and worth asking the question of a guiding general rule. Presumably, someone wants to eat less junk food because it’s become too much of a go-to option in their life for their preferences. This would be exactly the sort of situation where the rubber meets the (yellow brick) road, and a little prodding might actually be key to helping them think through exactly what they want out of this goal.