Have you ever eaten a lot of sugary stuff and still felt hungry? You’ve consumed lots of calories (probably too many), but your body doesn’t seem to care. What gives?
Basically, all calories aren’t the same. Our bodies have a mechanism called satiety that will stop us from eating more than we need, but it has more to do with our consumption of certain macronutrients than with calories or physical volume, and ultra-processed junk foods supply a much lower amount of those nutrients. Jeremy Furtado, a senior research scientist at Harvard University, explains it this way: “Frequently, the failure of foods to produce satiety is that they are deficient in fiber, that they are too easily digested, or that they do not provide a steady supply of calories into the body during digestion.”
For example, both about 15 cups of spinach or two Oreos contain 100 calories. The spinach will physically fill our stomachs with more food, plus dietary fiber and vital, naturally occurring nutrients. Unfortunately, the Oreos give us little more than intense levels of simple carbohydrates, which provide quick bursts of energy for short periods. And junk foods usually consist of cheap, low-quality and highly processed ingredients to begin with.
A food classification system used by the World Public Health and Nutrition Association called NOVA categorizes food into four groups: unprocessed or minimally processed foods (olives), processed culinary ingredients (olive oil), processed foods (whole grain bread, canned vegetables) and ultra-processed foods (all our favorite packaged chips and cookies, plus many fast foods and frozen meals). Any form of processing can affect our food’s nutrition ― milling grains or blanching vegetables can destabilize vitamins ― but ultra-processed foods go through a much more complex system that it’s probably best to not even think about.
Something else to consider — ultra-processed foods can contain as much as eight times the amount of sugar as whole foods, yet low-sugar and sugar-free junk foods are just as nutritionally empty.
The bottom line — junk foods are very well named.
For more depressing details about what we eat, see “Here’s Why You Don’t Feel Full After Eating Junk Food” by Katy Severson (https://www.huffpost.com/entry/feel-full-after-junk-food_l_5c76b279e4b08c4f555650fc?)