Junk food is an informal term applied to some foods that are perceived to have little or no nutritional value (i.e. containing “empty calories” – which means the food is loaded with calories and provide little or no other nutrients); to products with nutritional value, but also have ingredients considered unhealthy when regularly eaten; or to those considered unhealthy to consume at all. The term was coined by Michael Jacobson, director of the Center for Science in the Public Interest, in 1972.
Junk foods are typically ready-to-eat convenience foods containing high levels of saturated fats, salt, or sugar, and little or no fruit, vegetables, or dietary fiber; and are considered to have little or no health benefits. Common junk foods include salted snack foods like chips (crisps), candy, gum, most sweet desserts, fried fast food and carbonated beverages (sodas) as well as alcoholic beverages. High-sugar cereals are also classified as junk food.
"Only in recent years have taste receptors been identified. One of the first breakthroughs in taste research came in 1974 with the realization that the tongue map was essentially a century-old misunderstanding that no one challenged. Wine glasses are said to cater to this arrangement. The tongue map is easy enough to prove wrong at home. Place salt on the tip of your tongue. You'll taste salt. For reasons unknown, scientists never bothered to dispute this inconvenient truth," wrote Christopher Wanjek in LiveScience.com.
Did you know that the average American eats about 25 pounds of candy per year? What’s more, each American will consume about 45 slices of pizza annually. Now that’s a lot of sweet and salty goodness!
A report published in the Journal of the Federation of American Societies for Experimental Biology suggests that babies of mothers with a high-sugar and high-fat diet while pregnant are more prone to junk food themselves. The study was conducted on rats and suggests that "infants whose mothers eat excessive amounts of high-fat, high-sugar junk foods when pregnant or breastfeeding are likely to have a greater preference for these foods later in life."
A 2008 report suggests that mothers who eat junk food while pregnant or breast-feeding have children who are more prone to obesity. The children are also more prone to diabetes, raised cholesterol, and high blood fat.
A study by Paul Johnson and Paul Kenny at The Scripps Research Institute suggested that junk food consumption alters brain activity in a manner similar to addictive drugs like cocaine or heroin. After many weeks on a junk food diet, the pleasure centers of rat brains became desensitized, requiring more food for pleasure. After the junk food was taken away and replaced with a healthy diet, the rats starved for two weeks instead of eating nutritious fare. A 2007 British Journal of Nutrition study found that mothers who eat junk food during pregnancy increased the likelihood of unhealthy eating habits in their children.