I have a similar problem... I can eat on pointe all week, then have an awful weekend...
Can you manage the splurge day? Some of my most painful logging - but the most helpful is when I look those choices square in the face and own them. But then an amazing thing starts to happen - instead of being owned and shamed by that splurge (my point of view) -instead of feeling controlled by my bad choices, calling it out puts me back into the driver's seat. I can use my WP. I can exercise a little more. I *can* flex around those trips to Olive Garden... and learn that maybe 1/2 a breadstick will be enough of a taste for me to slowly eat and be content. Or maybe that bite of breadstick leads me to 3 whole breadsticks and I should avoid it.
And if I can't shuffle WP and EP enough, I can learn how to manage choices better (1/2 breadstick? No breadstick? Breadstick basket moved to the next county?) And I can eat "cleanly" the rest of the week to try to balance it the best I can.
Another help for me was scouting out nutritional information *before* we leave for the restaurant. If I'm hungry and looking at a menu, it's game over for me. But if I know ahead of time that when my girlfriends want to eat at Panera I'm ordering Black Bean Soup (and have a backup in case it's not on that day) and a salad... it puts me in control. If I wait until I'm hungry my brain gets left behind. (And sometimes the best choices aren't the obvious ones. "Healthy" sounding salads are more often than not, land mines!)
What started happening was after a few trips out, this lunch group started cycling through the same restaurants. And I already knew my Best Choice. And it wasn't like I was eating there every day, so it worked out. And after I made goal (this was before baby #2
)it freed up a few choices.
Hope this helps!