Using the word "waver" for moving away from diet

Question

Context: Chatting with a friend on Whatsapp. We both were following a diet plan, but today I didn't commit to it due to a family occasion.
How do I communicate this properly:
"Today went well, but wavered on the diet" <-- not sure if this is a correct sentence or if it expresses the fact that I ate something away from my planned diet

Answer 1

To me that sentence is correct and communicates what you are hoping it does. Put a little more formally you might say 'Today went well, but I wavered on my diet.' But it's fine for a WhatsApp message. Other common options for something like this are 'I didn't stick to my diet' or 'I didn't follow my diet.'

Answer 2

Another verb frequently used in that context is break.

I had to break the diet because of a family gathering where I was expected to eat some cake my aunt had made and try some of the sauce my sister-in-law had made and drink some of the home-brewed beer my brother was excited about and ...

wavered can be used but it suggests you were having doubts whether to remain on the diet.