At some point this holiday weekend, despite your steadfast resolutions to eat better this year, you may find yourself drunkenly ordering a pizza or nursing a hangover with a fatty egg and cheese sandwich at your local greasy spoon. Why does alcohol ruin our best-laid dietary plans? And does a calorie-laden breakfast actually help dull the pain from a night of revelry?

A small study published by Scottish researchers in 2001 looked at how alcohol affected the appetites of 26 male volunteers. The men visited the lab three times and were given either a glass of nonalcoholic lager or nonalcoholic beer spiked with alcohol, then treated to a hearty buffet lunch.

As the researchers reported in the journal Physiological Behavior, when the men were given alcohol, they ate significantly more at lunch, consuming an average of 30 percent more calories of food.

But what’s behind the craving for fatty foods? Some scientists think that alcohol-weakened inhibitions (like the resolve to keep your New Year's resolution to lose weight) are to blame. Others look to a more biochemical explanation.

A 2004 study published in the journal Alcoholism: Clinical and Experimental Research and led by Princeton University scientists suggest that a brain chemical called galanin could be behind both fatty food cravings and a thirst for alcohol.

Galanin could also be the key to creating pharmaceutical treatments to combat chronic drinking. The Princeton-led team found that when they gave rats extra galanin and access to alcohol, they drank more alcohol during the day, neglecting their food and water. But when the rats were given a compound that blocked the effects of galanin, they ate and drank water normally.

"There seems to be a cycle of positive feedback," Princeton researcher Bartley Hoebel said in a 2004 statement. "Consumption of alcohol produces galanin, and galanin promotes the consumption of alcohol. That would perpetuate the behavior."

When more alcohol consumption seems unpalatable, we might turn to fatty food to placate the shrieking biochemical demon that demands satisfaction.

“Galanin increases appetite for fats, and consumption of fat causes more galanin to be produced," University of North Carolina researcher William Gruchow told Popular Science last December. "Alcohol intake also results in increased galanin production.”

So fatty food could be “helping” your hangover to some degree, but only because it’s helping you get your neurochemical fix.

Calorie-laden alcoholic beverages plus all that drunken and post-drinking snacking can take its toll on your health. And the “beer belly” isn’t limited to just beer drinkers, either.

London-based researchers from the Royal Free and University College Medical School investigated whether the type of alcohol a person drinks and whether it is consumed with meals or not can mediate the effects of alcohol on body weight and fat distribution. They measured alcohol intake, body-mass index, waist circumference, body fat percentage and waist-to-hip ratio for 3,327 older men in 24 British towns.

Higher alcohol consumption, which the researchers defined as greater than or equal to 21 units of alcohol per week, was positively associated with general heaviness, especially around the middle, “irrespective of the type of drink and whether the alcohol is drunk with meals or not,” the authors wrote.