What's wrong with processed food?

Question

Jamie Oliver always talks about how processed food is awful, and we should stop eating it.

By processed food he means food which is pre-prepared and contains additives. He instead insists that food cooked from fresh local ingredients is much healthier.

By reading the ingredients lists on the foods you buy, understanding what you are eating and cooking more fresh food for yourself and your family you can become empowered to make the right food choices. Ingredients lists shouldn't be a long list of unpronounceable things you've never heard of. Avoid processed foods and you will see and feel the benefits.
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An example of his claims is the following:

Well, I think it’s pretty simple really: forty years ago we ate mostly fresh, local food, and we knew where that food was coming from. But then fast and heavily processed foods crept in and totally changed our palettes and food businesses. And ultimately, this food is killing us. Obesity and weight gain are the most obvious symptoms, but the problem I have in telling this story is that there are also loads of skinny people suffering because the garbage they are eating is affecting them in a different, but equally dramatic way.

Is there any evidence that food containing preservatives is worse for our health than freshly cooked food?

For example, if I were to cook chicken nuggets from fresh ingredients would it be healthier than using pre-made ones?

Answer 1

The fact that the food is merely "processed" doesn't make it bad (the classic example is pasteurized milk - it is also a "processed" food; another is properly frozen vegetables).

What CAN make processed food worse than non-processed food is four factors:

• Addition of certain ingredients that aren't good for you either by their nature (trans-fats) or by the unnatural amount (sodium).

  The additives can be for preservation (e.g. sugar/sodium), or as replacement for easily perishable ingredients (e.g. trans-fats - see Wiki transfats article or http://www.nap.edu/openbook.php?isbn=0309085373&page=423), or to give taste/color (e.g. MSG - which doesn't seem to have a firm scientific consensus on long term effects but a proven potential for short term ill effects in some people).

• A combination of different ingredients may lead to unexpected chemical reactions producing resulting chemicals that may be harmful. A well known example is Sodium Benzoate turning into carcinogenic Benzene in certain conditions.

• The quality of ingredients in processed food may not be as high. When you get a hot dog, there's no way for you to examine the meat which went into it for quality as you would the meat you buy from the store. This is because the processing pretty much destroys most indicators of food quality by changing ingredients' texture, mixing them with other ingredients etc... This allows the manufacturer to use lesser-quality ingredient to contain costs (not necessarily pig snouts of urban legend, but just lesser quality cuts etc...).

• The processing destroys good/useful/healthy properties of food. E.g. heating destroys vitamins.

Answer 2

There are many flavors of problems associated with processed food. Some stem from the ingredients which more often have:

• High-fructose corn syrup (ridiculous how many things have this..)
• Hydrogenated ????? oil (vegetable, soybean, peanut,..)
• High sodium

The above are related to preservation mainly. Some companies will use lesser-known alternatives which essentially do the same things. The first two hurt by generally making bodies fatter when the same meal could usually be made without them. Peanut butter is a good example - natural varieties don't use hydrogenated oil whereas other use hydrogen to make the peanut butter and oil bond more permanently so you don't have to stir it.

The molecular effect of hydrogenated oil is to make peanut butter more like plastic than protein mixed with fatty acids in the oil. Your body stores this plastic-like substance in your cells and can give them trouble. High fructose syrups simply have gobs and gobs of sugar with a long shelf life. These syrups signal your body to store fat as well.

In addition to these there are a few other things to consider:

• Processed foods have severely "injured" molecule chains giving lower quality and amount of nutrients than whole foods or freshly cooked foods.
• Vegetables and meat in processed food is often of low nutritional quality due to factory-like mentality vs. farms and ranches
• MSG is more common
• Usually no enzymes survive processing (The US's general populace for example has a rather large enzyme deficiency)
• Fresh tasting food is really good :P

References update

1. High fructose corn syrup (and high levels of fructose in general) lead to obesity and other health issues by stimulating cellular mechanism
2. Hydrogenation's affect on nutrients
3. High sodium in processed foods
4. Break of complex carbs in processed foods.
5. Processed foods destroy nutrients
6. Amino acids are body cannot produce are called "essential amino acids."
7. "In other words, if your diet is predominantly based on cooked and processed foods, what seems to be relatively large protein consumption may be effectively considerably smaller." and other information.
8. This talks briefly of high-fructose corn syrup and MSG in processed foods.
9. Enzyme deficiency and poor digestion.
10. "Simply cooking or processing food can destroy many of the natural enzymes"
11. Extra reference with various related points.