Why you overeat on Mondays

Source: Best Health Magazine, January/February 2010

You’re good as gold all week, watching what you eat. So when Friday night comes, you take a break (and it’s true that treating yourself keeps weight off for the long term). But on Monday, don’t you find it’s tough to get back on track?

Science is giving an indication why. Normally, the hormone leptin signals to the brain you’ve eaten enough. But a recent animal study from the University of Texas Southwestern Medical Center at Dallas found that digesting palmitic acid (found in high concentrations in saturated fats) over a few days may inhibit leptin past the weekend.

‘On Monday, you probably won’t feel full when you eat, since the brain isn’t getting the signals,’ says researcher Deborah Clegg. So you may eat more than you normally would’and your weekend cheat backfires.

This research also found that monounsaturated fats and, specifically, oleic acid (a.k.a. omega-9s) don’t stop ‘full’ signals’so they’re the good guys. Karie Quinn, a Grande Prairie, Alta.-based dietitian, agrees: Monounsaturated fat helps you feel full. So don’t cross all fats off your diet. To avoid the Monday Diet Hangover, spread treats out. And simply knowing what saturated fat does to your brain may empower you to eat less of it.

Good vs. bad fats

Bad: Palmitic acid
This is found in saturated fats of animal products. Palm oil and coconut oil, used in packaged food like donuts, also contain this acid.

Good: Oleic acid
Favour vegetable-based oils, such as olive, corn and canola; they’re high in monounsaturated fats. Other sources are nuts and avocados.

This article was originally titled "Beware the ‘Monday Diet Hangover’," in the January/February 2010 issue of Best Health. Subscribe today to get the full Best Health experience’and never miss an issue!’and make sure to check out what’s new in the latest issue of Best Health.