Before You Dig In
Your brain's pleasure and reward centers light up, prompting you to really crave that mint chocolate chip -- even if you're not very hungry.
Fueling the fire: Your hippocampus, a key memory player, starts reminding you just how good ice cream tastes and how happy you felt the last time you indulged.
After the First Bite
Fat and sugar coat your tongue, igniting your taste buds and alerting the brain, This stuff tastes great! Your noggin churns out dopamine and other feel-good chemicals.
Your pancreas, meanwhile, is squirting out insulin, which moves sugar out of the bloodstream and into your tissues. (That's fine in small doses, but eating sugar too often can lead to a wacky metabolism, weight gain, or diabetes.)
To avoid overeating, your stomach starts releasing appetitecontrolling hormones, like ghrelin and peptide YY. Give them time: In one study, people who spent 30 minutes lingering over their ice cream felt fuller than those who ate the same amount in five minutes.
After a Few Minutes
Sensing the cold, your brain tries to warm itself. Enter a sudden, sometimes painful rush of blood through your head's main artery -- a.k.a. brain freeze. (Holding your tongue to the roof of your mouth can help.)
After an Hour
Protein, fat, and carbs are filling your body's quick-energy stores -- but only if you worked out earlier. If you didn't, those stores might be full, so your fat cells absorb the 300-plus calories instead.
The Next Day, and the Next. . .
Treating yourself now and then can amp up your mood, but research shows that slurping ice cream four or five times a week can dull the pleasure, causing people to eat more to get the same sense of satisfaction.
Before you scoop, look at your serving ware. One study found that people subconsciously helped themselves to 31 percent more ice cream when using a larger dish, and ate 15 percent more when the serving spoon was larger.
Sources: Linda Bartoshuk, Ph.D., University of Florida; Kyle S. Burger, Ph.D., Oregon Research Institute; Philipp Scherer, Ph.D., The University of Texas Southwestern Medical Center