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.
-- source

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.

enter image description here

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?

  • 6
    No discussion of this subject would be complete without reference to Dr. Weston Price's 1939 book, Nutrition and Physical Degeneration, in which the author establishes a clear relationship between the consumption of processed foods and the prevalence of degenerative diseases (e.g. dental cavities, arthritis) that he found to be rare or nonexistent in ethnically identical populations that had not yet deviated from their traditional diets. Commented Mar 27, 2011 at 3:09
  • 1
    You really need to add a link to a specific claim here - the question is completely subjective otherwise.
    – Sklivvz
    Commented Mar 27, 2011 at 8:57
  • @Monkey - "Diet sodas (also diet pop, diet, sugar-free, or light soft drinks, refreshments, or carbonated beverages) are typically sugar-free, artificially sweetened, non-alcoholic carbonated beverages generally marketed towards health-conscious people, diabetics, athletes, and other people who want to lose weight, improve physical fitness, or reduce their sugar intake" - en.wikipedia.org/wiki/Diet_soda . My understanding is that whatever sugar replcement they use isn't exactly considered very healthy, though I never bothered to find out since I hate the taste in the first place :)
    – user5341
    Commented Mar 27, 2011 at 11:14
  • @Monkey - see for example "DeNoon, Daniel J. Reviewed by Charlotte Grayson Mathis MD. "Drink More Diet Soda, Gain More Weight? Overweight Risk Soars 41% With Each Daily Can of Diet Soft Drink", WebMD Medical News (2005), accessed 2007-06-25" - webmd.com/diet/news/20050613/…. Sounds like there's a correlation but not a proven causation.
    – user5341
    Commented Mar 27, 2011 at 11:24
  • 6
    Without processing, how would we make beer?
    – oosterwal
    Commented Mar 29, 2011 at 13:41

2 Answers 2


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.

  • 4
    This answer is not properly referenced. Please add citations to support your claims! :-)
    – Sklivvz
    Commented Mar 27, 2011 at 9:09
  • 2
    @Sklivvz - added more
    – user5341
    Commented Mar 27, 2011 at 17:11
  • 1
    – Sklivvz
    Commented Mar 27, 2011 at 17:46
  • 3
    @Garet The site misrepresents how pasteurisation works. It also ignores that modern milk is instead micro-filtrated (at least here over in Europe …) and it gives a false reason why this is done (the reason isn’t to hide toxicity but to prolonge durability). Finally, it overpays organic milk’s pesticide freeness (there are other toxic substances in abundance in organic milk, e.g. dioxins) but that’s only to be expected for a organic food site. Commented Mar 28, 2011 at 12:54
  • 1
    @Konrad, @Garet - but natural milk is TASTIER! :) (spoken from experience). But yeah, Konrad is correct.
    – user5341
    Commented Mar 28, 2011 at 15:56

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.
  • 4
    This answer is not properly referenced. Please add citations to support your claims! :-)
    – Sklivvz
    Commented Mar 27, 2011 at 9:11
  • 2
    What do you mean by "injured" molecule chains? That makes no sense chemically. And enzymes you eat are broken down into amino acids and digested, we humans produce our enzymes ourselves, we don't take them up with our food.
    – Mad Scientist
    Commented Mar 27, 2011 at 9:14
  • 1
    @Garet Eh, FWIW I think it’s a good answer after you’ve added the references. Commented Mar 29, 2011 at 8:58
  • 1
    Not sure why there are so many downvotes. A comprehensive treatment is Pollan's book In Defense of Food, which is pretty sound scientifically (but not only about processed food). scholar.google.com/…
    – Ruben
    Commented May 29, 2011 at 11:23
  • 4
    @GaretClaborn Your biochemistry isn't very good. Enzymes are usually just proteins or structures built on proteins that perform a biological function by catalysing some important reaction. They are destroyed even more effectively by your stomach acid as they are by any industrial process or cooking.
    – matt_black
    Commented Jan 17, 2012 at 0:17

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .