Pictures of to-die-for food and beverages clog the news feeds of 63 percent of social media users ages 13 to 32. As of May 2015, #foodporn, a hashtag used to mark photos of snacks and meals, was tagged 54 million times on Instagram alone. Although you cannot reach into the screen and make the depicted meal in real life, the mere pleasure of viewing such tasty fare can be all it takes to stir up your appetite and compel overindulging. Indeed, 70 percent of household meals in America are influenced by digital media in some way, says food psychologist and researcher Brian Wansink.

New research published in the October 2015 issue of the journal Brain and Cognition found that the brain undergoes dramatic neurophysiological changes in response to food images that exacerbate physiological hunger. According to the study, “external food cues, such as the sight of appetizing food, can evoke a desire to eat, even in the absence of hunger.”

Study authors conducted a meta-analysis of neuroimaging of more than 1,500 subjects to assess the neural response to visual cues as related to their current weight and satiety level. Obese individuals were shown to be more responsive to food cues when in a satiated state than healthy weight individuals. When hungry, neural activation of reward centers were observed in obese individuals while the areas of the brain associated with cognitive control were activated in healthy-weight individuals. This branch of the study suggests that the weight of the viewer influences the brain’s response to food images.

A 2014 meta-analysis showed that higher-BMI participants who viewed pictures of healthy foods while thinking about the pleasure that would be achieved from consumption experienced greater activation in areas of the brain associated with cognitive control and the anticipation of reward when compared with lean participants. Conversely, when the same images were viewed while focusing on the possible health benefits of the food, participants with a higher BMI experienced less activity in these same areas of the brain. These results suggest that individuals with a higher BMI often dismiss or ignore the health benefits of food, and that they make food choices primarily based on food’s perceived tastiness.

How to avoid gaining weight

A report released in November found that obesity is on the rise. Although sugar and soda consumption has been successfully reduced over the last 15 years— down more than one-quarter since 1999, the number of obese Americans continues to climb. In 2004, a reported 32 percent of Americans were obese. That number climbed to 35 percent in 2012, and now a 2014 report shows an obesity rate hovering near 40 percent.

Globally, obesity is on the rise because most people live in what scientists are calling an “obesogenic environment,” or surroundings that promote obesity. The overabundance of fast-food joints, ready-made meals, and gourmet take-out dinners make it easy for anyone to have junk food at a relatively low cost. Fewer people eat home-cooked meals, and the rise of on-the-go meals and emerging technologies mean that more and more people are engaging in distracted eating— another factor that contributes to weight gain. You are in control of several factors in your environment, including what you choose to consume via social media.

Take these 5 steps to make sure your social media environment promotes good health:

1. Shop local and organic
Choose fresh, whole foods, like fruits, vegetables, and lean, organic meats. Find the farmers market near you or an organic grocer.

2. Skip processed foods
Shop the perimeter of the grocery store to stay away from the boxed, canned, and frozen foods that can add empty calories and toxins to your diet.

3. Cook your meals at home
Limit dining out to special occasions. Skip the drive-thru, or at the very least save on-the-go meals for true emergencies when you won’t have time to whip up a home-cooked meal.

4. Avoid distracted eating
Don’t eat while watching TV, working, driving, or surfing on your computer, phone, or tablet.

5. Regulate your social media feed
If “food porn” makes your stomach growl, consider censoring you feed.