You’ve even been eating healthier this summer and are probably in the middle of getting a rockin’ bod with our Best Bodies challenge. So what could be the culprit behind those few extra pounds you’ve put on? Here’s the hard truth: drinks after work may be to blame, but not in the way you think.

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According to a recent study, alcohol exposure sensitizes the brain’s response to food aromas and increases caloric intake. That means that those pre-dinner rooftop drinks could be affecting the cravings in your belly, convincing you to place a heartier dinner order than you normally would. “The ‘aperitif effect,” or consumption of more food after drinking, has been known for some time now, but there has never been a consensus on what causes you to eat more—what alcohol is doing to lead to this,” said William J. A. Eiler II, PhD, lead author of the study. “Our findings lead us to believe that alcohol may make the aromas from food more appealing.  As a result of the food smelling better, we may be compelled to eat more of it.”

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The study involved 35 healthy women, who received alcohol via an IV drip on one visit and a placebo during another. Wondering why they didn’t just line up glasses of wine? The goal of the test was to look solely at the brain’s role with alcohol consumption, minus any interference from the stomach. The participants’ brain responses to food and non-food aromas were then measured in response to two lunches: pasta with Italian meat sauce and beef with noodles. The study’s findings indicated that participants ate more when they received intravenous alcohol.

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So how much alcohol until you notice the effect? “That is a good question and one that will have to be answered by further research,” says Eiler.  “In our study, we maintained all our subjects at a breath alcohol concentration of 0.05 percent, which is equivalent to a couple of glasses of wine. I would hazard to say that there is likely a ‘sweet spot’ where drinking before a meal increases your consumption, with too little having no effect and too much leading to a decrease in eating.”

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For those of you who are keeping an eye on your weight, be aware of the amount of and what types of pre-meal beverages you’re consuming. For example, your favorite craft beer might be pretty calorically dense, explains Eiler. “This can be compounded by the aperitif effect as you are not only increasing your caloric intake by drinking, you are likely to indulge a little more while eating your meal,” he says. A solid rule of thumb: When you know you’ll be drinking, “plan ahead by preparing smaller portions or making healthier choices.”