Processed foods are bad. They are a major contributor to obesity and illness around the world.

Most foods we eat are processed in some way. Apples are cut from trees, ground beef has been ground in a machine and butter is cream that has been separated from the milk and churned.

But there is a difference between mechanical processing and chemical processing.

If it's a single ingredient food with no added chemicals, then it doesn't matter if it's been ground or put into a jar. It's still real food.

However, foods that have been chemically processed and made solely from refined ingredients and artificial substances, are what is generally known as processed food.

Here are 8 ways that processed foods are bad for your health.

1. High in sugar and high-fructose corn syrup

Processed foods are usually loaded with added sugar... or its evil twin, High Fructose Corn Syrup.

It is well known that sugar, when consumed in excess, is seriously harmful.

As we all know, sugar is "empty" calories - it has no essential nutrients, but a large amount of energy.

But empty calories are really just the tip of the iceberg when it comes to the harmful effects of sugar. Many studies show that sugar can have devastating effects on metabolism that go way beyond its calorie content.

It can lead to insulin resistance, high triglycerides, increased levels of the harmful cholesterol and increased fat accumulation in the liver and abdominal cavity.

Not surprisingly, sugar consumption is strongly associated with some of the world's leading killers... including heart disease, diabetes, obesity and cancer.

Most people aren't putting massive amounts of sugar in their coffee or on top of their cereal, they're getting it from processed foods and sugar-sweetened beverages.

2. Engineered for overconsumption

We all want to eat good food. That's just human nature.

Evolution provided us with taste buds that are supposed to help us navigate the natural food environment.

Our appetite gravitates towards foods that are sweet, salty and fatty, because we know such foods contain energy and nutrients that we need for survival.

Many processed foods have been engineered to be so incredibly "rewarding" to the brain, that they overpower anything we might have come across in nature.

We have complicated mechanisms in our bodies and brains that are supposed to regulate energy balance (how much we eat and how much we burn) which, until very recently in evolutionary history, worked to keep us at a healthy weight.

There is quite a lot of evidence that the reward value of foods can bypass the innate defense mechanism and make us start eating much more than we need, so much that it starts to compromise our health.

This is also known as the "food reward hypothesis of obesity."

The truth is, processed foods are so incredibly rewarding to our brains that they affect our thoughts and behavior, making us eat more and more until eventually we become sick.

Good food is good, but foods that are engineered to be hyper rewarding, effectively short circuiting our innate brakes against overconsumption, are NOT good.

3. Contain artificial ingredients

If you look at the ingredients label for a processed, packaged food, chances are that you won't have a clue what some of the ingredients are.

That's because many of the ingredients in there aren't actual food. Rather, they are artificial chemicals that are added for various purposes.

Highly processed foods often contain:

• Preservatives: Chemicals that prevent the food from rotting.
• Colorants: Chemicals that are used to give the food a specific color.
• Flavor: Chemicals that give the food a particular flavor.
• Texturants: Chemicals that give a particular texture.

Keep in mind that processed foods can contain dozens of additional chemicals that aren't even listed on the label.

For example, "artificial flavor" is a proprietary blend. Manufacturers don't have to disclose exactly what it means and it is usually a combination of chemicals.

For this reason, if you see "artificial flavor" on an ingredients list, it could mean that there are 10 or more additional chemicals that are blended in to give a specific flavor.

Of course, most of these chemicals have allegedly been tested for safety. But given that the regulatory authorities still think that sugar and vegetable oils are safe, I personally take their "stamp of approval" with a grain of salt.

4. People can become addicted to junk food

The "hyper-rewarding" nature of processed foods can have serious consequences for some people.

Some people can literally become addicted to this stuff and completely lose control over their consumption.

For many people, junk foods can hijack the biochemistry of the brain, leading to downright addiction and cause them to lose control over their consumption.

5. Often high in refined carbohydrates

There is a lot of controversy regarding carbohydrates in the diet.

Some people think that the majority of our energy intake should be from carbs, while others think they should be avoided like the plague.

But one thing that almost everyone agrees on, is that carbohydrates from whole foods are much better than refined carbohydrates.

Processed foods are often high in carbs, but it is usually the refined variety.

One of the main problems is that refined, "simple" carbohydrates are quickly broken down in the digestive tract, leading to rapid spikes in blood sugar and insulin levels. This can lead to carb cravings a few hours later when blood sugar levels go down again. 

Not surprisingly, eating a lot of refined carbohydrates is associated with negative health effects and many chronic diseases.

Do NOT be fooled by labels like "whole grains" that are often plastered on processed food packages, including breakfast cereals.

These are usually whole grains that have been pulverized into very fine flour and are just as harmful as their refined counterparts.

If you're going to eat carbs, get them from whole, single ingredient foods, not processed junk foods.

6. Low in nutrients

Processed foods are extremely low in essential nutrients compared to whole, unprocessed foods.

In some cases, synthetic vitamins and minerals are added to the foods to compensate for what was lost during processing.

However, synthetic nutrients are NOT a good replacement for the nutrients found in whole foods.

Also, let's not forget that real foods contain much more than just the standard vitamins and minerals that we're all familiar with.

Real foods, like plants and animals, contain thousands of other trace nutrients that science is just beginning to grasp.

Maybe one day we will invent a chemical blend that can replace all these nutrients, but until that happens the only way to get them in your diet is to eat whole, unprocessed foods.

The more you eat of processed foods, the less you will get of vitamins, minerals, antioxidants and various trace nutrients.

7. Low in fiber

Fiber, especially soluble, fermentable fiber, has various benefits.

One of the main ones is that it functions as a prebiotic, feeding the friendly bacteria in the intestine.

There is also evidence that fiber can slow down the absorption of carbohydrates and help us feel more satisfied with fewer calories. The fiber that is found naturally in foods is often lost during processing, or intentionally removed. Therefore, most processed foods are very low in fiber.