Munching on a bag of Doritos while guzzling a beer or nibbling at cheese cubes with a glass of wine in hand may be pleasurable, but it can come with unwanted side effects, including increased bloat, calories and weight gain.

That much we may have already experienced firsthand. A more interesting question is: Why does alcohol give us the munchies in the first place?

One of the simplest explanations as to why we eat more when we drink is that alcohol lowers our inhibitions and can decrease our defenses when it comes to portion control and making healthy eating choices. With a drink in hand, you're more likely to grab handfuls of nuts, chips, bread or whatever is staring you in the face without really giving it a second thought.

"Studies show that people will consume more at meals when they're including alcohol or have been drinking before the meal," said Ginger Hultin, a registered dietitian and author of the blog Champagne Nutrition.

Hultin, who is also a spokeswoman for the Academy of Nutrition and Dietetics, said that in addition to lowering our defenses, there is evidence that alcohol can influence hormones tied to satiety, or feeling full. For example, alcohol may inhibit the effects of leptin -- a hormone that suppresses appetite -- and glucagon-like peptide-1 (GLP-1), a hormone that inhibits food intake, she explained.

There might be other mechanisms at play, too. Some research suggests that alcohol might stimulate nerve cells in the brain's hypothalamus that increase appetite. According to one study, neurons in the brain that are generally activated by actual starvation, causing an intense feeling of hunger, can be stimulated by alcohol.

"Animal research shows that, independent of other factors, when alcohol stimulates this part of the brain, it can trigger a sharp increase in appetite, which can lead to overeating," Hultin said. "Instead of the body recognizing 'I just got a lot of calories, so I have fuel and I'm full,' the opposite occurs. Though calories have been ingested, the brain is triggering more food intake."

Alcohol can also lower blood sugar, which can cause us to crave sugar and carbs. "Drinking alcohol can impair the liver's ability to release the right amount of glycogen, or stored glucose, into the blood to keep blood glucose levels stable," Hultin said. People with diabetes are at even higher risk for low blood sugar levels when they drink, according to Hultin, particularly when consuming alcohol on an empty stomach.

But another challenge with alcohol -- which is different from drugs like pot -- is that alcohol itself is high in calories, with 7 per gram. That's more calories than you get per gram of protein or carbs, which have 4 calories per gram each.

A 5-ounce glass of wine might have only 120 or 125 calories, and a light beer even less, but mixers, juice, soda, syrups, cream and coconut all pack sugar and fat calories on top of alcohol, Hultin explained. "Margaritas and pina coladas are classically very high in calories, with some estimates pushing up towards 500 calories for one drink, depending on the size and how it's made."

Tips to curb alcohol munchies

Before you take your next sips of wine, beer or spirits, learn some helpful tips to curb alcohol munchies.

Drink with a balanced meal. "Include whole-grain, complex carbohydrates, healthy fat and protein so that your body is nourished and satiated from the start," Hultin said. This will also ensure that your "munchies" aren't actual hunger, reflecting the body's need for a meal.

Don't have unhealthy snacks lying around. "Chips, candy, pizza and other desserts are easy to grab if your appetite starts to rise as you're drinking," Hultin said. These calorie-dense foods can pack on pounds over time. If you're at a restaurant, ask the server to take the bread basket away.

Make healthier options more accessible. If you know that you will be tempted to eat when drinking, take out hummus with chopped veggies, fruit or air-popped popcorn to snack on.

Hydrate. "Alcohol is dehydrating, so make sure to sip on plain or sparkling water if you find yourself wanting to snack," Hultin said. This will not only save you calories from more alcohol, it will give your hands something to hold if you find yourself reaching for snacks when you know you're not actually hungry.

CNN

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