And, now I know it’s kinda not my fault.  Kinda.

Findings from a new study suggest that some fats cause our brains to turn off the “I’m full” signal that tells us when to stop eating.

Here’s what they think happens: we eat the fat, it goes to our brains.  Once they get there, the fat molecules tell the body to just ignore the appetite-suppressing signals from leptin and insulin (those pesky weight regulation hormones).  This biological fake-out, the study says, is caused not by just any fat, but by palmitic acid – a fatty acid that is found in foods with high saturated-fat content.  Oleic acid, (a healthy monounsaturated fat, found in olive oil) did not cause this effect.

And, the worst part?  The effect can last for three days.  THREE DAYS.  Which means that if I gorge myself on saturated fats on Friday night, on Monday my brain still won’t know when my body’s had enough food.  I guess this explains why it’s so hard to get back on track after a weekend of bingeing.  And, now that I think about it, why it’s probably NOT a good idea to eat your way through the wekeend before you start a new diet.  You’re literally setting yourself up to fail.

This study was conducted in rats, of course, but it makes sense to me.  Actually, I know it’s true, from personal experience.  I am a member of Weight Watchers, and I weigh in on Thursday nights.  Following my Thursday night meeting, I am starving.  Sometimes I eat pizza, wings, ice cream, etc. that night, telling myself I’ll get back on track in the morning.  Other nights, however, I stay completely on program and have a healthy dinner. Guess what happens.

The weeks that I pig out, I can’t really get back on program until Sunday or Monday.  I am ravenously hungry all weekend, and I cannot control what I eat (I know this sounds completely stupid, but this is why I have always had a weight problem).  The weeks I eat normally, I can stay on program all weekend, even while eating out.  Now, I know exactly why that is, and I will hopefully be able to apply this new knowledge in the future.

Here’s the full press release, from the University of Texas Southwestern Medical Center.

Fat Rat
Fat Rat