So I'm in the shower stall at the gym, and just for a minute I think I'm not going to be able to pull my jeans over my thighs.

The jeans have some stretch to them, so intellectually I know the problem is that I haven't toweled off enough, but after seeing my belly in the mirror fronting the fly machine, I fear I have reason to panic. I really don't want to go to the office in my workout pants.

By the time I inch my jeans up over my hips, I'm drenched in anxious sweat and tempted to take another shower, but there's no way the jeans are coming off again.

It's scary how a skipped workout here and a slice of birthday cake there can so rapidly turn into a downward spiral where the gym's a dim memory and dessert is my primary motivation for making it through the day.

I know from talking to my girlfriends that diet fatigue is a common phenomenon. Unfortunately, we've had a hard time figuring out what to do once we've run out of steam.

My problem is that I'm an all-or-nothing type of person, and lately I've been doing a whole bunch of nothing ... except for eating, that is.

Lots of people are good at moderation. They leave food on their plates — even dessert! — and if they're pressed for time, they'll do an abbreviated workout rather than skip it entirely.

My brain doesn't work that way.

If I don't have time for a morning workout, chances are I won't squeeze it in later.

If I've already messed up the day because I didn't exercise, I figure I might as well grab a doughnut for breakfast, which makes it easier for me to excuse the french fries at lunch and the ice cream after dinner.

The next morning I'll be so bloated and depressed that I'll reach for fat clothes instead of my workout gear.

I've been down this road before and despite knowing that the only things lying ahead are tent dresses, elastic waistbands and baggy tees, I'm having a hard time changing direction.

The nagging wakeup calls are too easy to ignore. A baggy shirt will hide a pinching waistline. Watchbands (and belts) are conveniently adjustable. As for double chins, well, you can't see them in the mirror if you angle your head just so.

If only the camera would lie as well as the mirror, I could happily remain in denial. Unfortunately, while looking over photos from a recent visit with an out-of-town friend, I couldn't even concentrate on our happy faces because my eyes were drawn instead to the way my T-shirt accentuated the rolls it was supposed to hide, and the way my high heels drew attention to my puffy ankles instead of lengthening my legs.

Presented with this evidence, I have two choices: I can console myself with potato chips and cake, or I can start dragging my butt back to the gym regularly.

For now, I'm back in the gym, but you can bet I'll be packing my fat jeans in my gym bag until I start seeing some results.

Reach Treena Shapiro at tshapiro@honoluluadvertiser.com. Read her daily blog at blogs.honoluluadvertiser.com.