Factory producing seed oils

Researchers debate the fundamental causes of the obesity epidemic, and dietary changes are the most likely reasons. But which changes? Experts have pointed their fingers at sugar, refined carbs, excess fat, not enough protein, too little exercise, and many others. But one of the main causes may be hiding in plain sight, since there’s good evidence that vegetable oils cause obesity, alone or in combination with other nutrients.

Vegetable oil consumption has increased

Vegetable oils are better termed industrial seed oils, since they are not made from vegetables but from the seeds of grains via an industrial process. They are not natural foods, since the means of making them in any quantity have only been available for about the past 120 years. Consumption of seed oils has risen dramatically in recent decades. See charts below, showing annual seed oil consumption per person in kilograms. (Source.)

For comparison, the chart below shows other food consumption trends in recent decades. The consumption of dairy, beef, and pork are all down; grains are higher, and sugar about the same. Soy oil is way up, as is chicken, which perhaps not coincidentally also contains large amounts of the omega-6 fats that are also found in seed oils.

Linoleic acid is the main omega-6 fatty acid found in seed oils, and its consumption has greatly increased.

Note a couple of things about this chart. 1) The U.S. has the highest rate of obesity and also the highest linoleic acid consumption. 2) The chart only begins in 1960, so compared to earlier, say 1900, current consumption is way higher.

“The most striking modification of the US food supply during the 20th century was the >1000-fold increase in the estimated per capita consumption of soybean oil from 0.006% to 7.38% of energy.” (Source.) Other estimates put consumption as high as 20% of calories.

Vegetable oils are obesogenic

Suppose we set up a 3-way contest among nutrients to see which one could get mice the fattest. The nutrients are soybean oil, coconut oil, and fructose (of which 50% of table sugar is composed).

The clear winner is soybean oil: Soybean Oil Is More Obesogenic and Diabetogenic than Coconut Oil and Fructose in Mouse.

Soybean oil made mice obese, induced diabetes, and caused fatty liver.

Linoleic acid, the main omega-6 fat, elevates endogenous cannabinoids and induces obesity at a concentration of 8% of calories. When the concentration is only 1%, it does not induce obesity.

Supplementation of the diet with soybean oil increases triglycerides, a sign of insulin resistance. Furthermore, it stimulates macrophage foam cell formation, a crucial step in atherogenesis leading to coronary heart disease.

Blame it on the American Heart Association

Why did the consumption of soybean oil increase so dramatically? In part because the American Heart Association advised Americans to replace saturated fat with vegetable oils.

Americans took that advice, and soybean oil consumption skyrocketed.

The recommendation of the AHA to replace natural foods with an industrial product that humans didn’t evolve to eat – let’s just say that it didn’t turn out well.

Vegetable oils cause obesity

Vegetable oils cause obesity in animals and are likely involved in the obesity epidemic in humans.

These seed oils are ubiquitous; besides obvious sources like bottles of vegetable oil and margarine, virtually all processed food contains them. To stay healthy and lean, or to return to that state, avoid them.

Eat whole, unprocessed foods, and to cut back even more on omega-6 intake, avoid chicken and most nuts.

Avoiding seed oils to maintain leanness and health should be done in conjunction with avoidance of sugar and refined carbohydrates.

PS: Besides avoiding seed oils, a lot more on what you can do for health and long life is in my book, Stop the Clock.

PPS: Check out my Supplements Buying Guide for Men.

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  1. Drifter says:

    If I remember correctly, and I think that again Cate Shanahan has written extensively on this along with many others, corn and soybean oil are particular culprits in visceral (organ) fat which accounts for the semi-ubiquitous pregnant look. This type of body fat is apparently much worse than non-organ fats, even when the person is not officially obese. Another interesting point Dr. Shanahan has raised is that seed oils are stored in the body as a different type of fat which specifically creates the cellulite-looking fat and unattractive skin, whereas the same amount of fat in a person eating healthy fat will create healthy-looking toned skin.

  2. Montgomery says:

    Thank you for that informative article; great material and concise presentation, yet all the sources neatly
    listed – no time wasted with bloated wording, yet all data in depth available to convince.
    Truly outstanding, especially in today’s information overload.

    But I wonder if food selection is the only issue with American obesity:

    37% of Americans think that only ‘genetically modified’ food contains any genes.


  3. Bill says:

    Good day PD, well presented..A couple of coments from an Australian perspective.
    1: It’s a pity that the charts all end in 2000..-17 years ago.. I wonder what has happened since then.

    2; Here soy bean oil is rare. Not many people use it at home. The industrial oils usually used here are canola which is widely grown and cotton seed oil. There isa big cotton growing industry here. Most of it is GMO cotton. And a lot of the seed is processed for it’s oil and sold as vegetable oil.
    3: I think that there as many obese Australians now as in the USA ! I see them each & every day…And unfortunately many of them are older folk. In fcat I saw one bloke this morning at the gym moving very slowly on the cross trainer. Now he really needs to be reading here and your books ! But how to do it.

  4. Bill says:

    I see also that poultry consumption rocketed up as well. But this is a marker of industrial farming of chickens in big sheds where they never seen the sun or grass and get fed on grain & soybeans !

    So a question : is meat from animals fed on such crap food also crappy for humans ? I think so as the aim is to make the chooks ( and cattle and pigs etc. ) fat quickly.

    Another garbage in = garbage out with human health ?

    • P. D. Mangan says:

      Meat from animals fed crap is somewhat bad for humans, but it’s a matter of quantity. You get far more from ingesting oils than you do from meat.

  5. TeeDee says:

    Thank you for this well written, concise article, P.D. As someone else mentioned, you didn’t allow it to get bloated and it gets right to the point without missing important details (mentioning that obesity didn’t happen at 1% consumption as it does at 8% in animal studies is one of the details that is important to know; even if one plans to never consume these oils again).
    Must admit, I’m not thrilled to read about chicken, as I love making baked spicy chicken wings for a treat. I’m wondering if it would help to take some premium Omega 3 oil with the chicken to balance things out? Or am I grasping at straws? Any thoughts about that?

    • P. D. Mangan says:

      Hi TeeDee, personally I’ve cut way back on eating chicken in the past few months, because of omega-6 content. I also regularly take fish oil, about 1 tsp of cod liver oil 3 times a week. So I try to minimize my omega-6 intake, and add the omega-3 for balance. It’s important not to overdo the fish oil. IMO by far it’s more important to minimize omega-6. I do still eat chicken from time to time – at my favorite Mexican restaurant I order the grilled chicken every time, as it’s reasonably low-carb and paleo; but I only go there once every couple of weeks. I also rarely eat nuts for the same reason.

      • Marco says:

        Hi P.D.
        Thanks for the well written post, as usual.
        Could you explain why “it’s important not to overdo the fish oil”?

        • P. D. Mangan says:

          Hi Marco. Polyunsaturated fats, both omega-3 and -6, oxidize readily, which is one of the reasons that large amounts of oils containing omega-6 are dangerous for health. Also, the body requires both of them, but the amounts needed are small. While large amounts of fish oil could help overcome high omega-6 intake, that’s not an optimal situation. That’s why I always say the best first move is to cut omega-6 intake as much as possible, then to supplement with fish oil in relatively low doses. For example, I take 1 tsp cod liver oil about 3 times a week, maybe more sometimes, and that gives me the same amount of omega-3 as if I were eating salmon a couple times a week, an amount known to be associated with better health and lower disease risk. Some doctors prescribe large amounts of fish oil to lower triglycerides, but in that case, it would be better to cut carbs and lose weight first, rather than just add a lot of fish oil. So in all cases (that I can think of), cutting the omega-6 is best to do first, as well as cutting out processed food and refined carbs.

      • TeeDee says:

        P.D. I truly appreciate the fact that you’re not afraid to get specific about what you eat, including supplements. I understand that we ultimately need to figure out what works best for us as individuals, but with so much conflicting information out there, it’s so good to see a real life example. Thanks again for all you do.

  6. ConantheContrarian says:

    Dennis, I am trying to confine the oils used in cooking and eating to olive, coconut, and palm oil. Tell me, is avocado oil alright? It doesn’t seem to be an industrial oil. Also, I have “found” a margarine that is coconut and palm oil only, Nutiva Buttery Spread, but I cannot find it being sold anywhere.

    • P. D. Mangan says:

      Hi Conan. Avocado is pretty good, with about 13% polyunsaturated fat (12% omega-6), that compares to about 10% for olive oil. Personally, where oil is needed, I prefer to use olive oil, and if cooking, coconut oil or butter. Sometimes I scramble eggs in olive oil.

  7. Michael says:

    You mention you don’t eat nuts because of Omega 6 content. I’ve seen studies finding a relationship between nut consumption and longevity though. Do you have an opinion on that?

    • P. D. Mangan says:

      I do have an opinion as a matter of fact. My opinion is that for most people, substituting nuts for what they usually eat (processed garbage, in other words) is a net benefit. They supply some omega-3, as well as magnesium and other nutrients. We here at Rogue Health are aiming for the next level, however, and IMO if I were to eat nuts instead of meat, fish, dairy, and vegetables would be a net detriment, because it would add omega-6, not to mention a ton of calories. I’ll eat a few on occasion, but the practice of eating handfuls of them is likely not to my benefit.

  8. Robert says:

    Hi Dennis, thanks again for your writing.

    You mention youve cut down on chicken intake. What do you eat to substitute for the dietary protein and fat then?

    Cheap beef? Fish? More coconut/olive oil? Just curious.

    • P. D. Mangan says:

      Hi Robert. I’m eating a lot more beef these days, mostly ground beef but also a steak here and there. Grilled hamburgers are mighty tasty, especially with some cheese; I’m always surprised how good they are. I eat some pork too, and about the only time I eat chicken is if I’m eating out, as it tends to be the most inexpensive menu item at the couple of regular places I go to. I’m also giving more beef and less chicken to my cat; I was giving him mainly chicken gizzards when I had that “D’oh!” moment, and he now gets, along with the gizzards, ground beef and beef liver, sometimes some fish. (Beef liver is under $2 a pound, and a can of mackerel is cheaper than commercial cat food.)

      If I get a dry piece of meat, I put butter on it. Cooking done with olive or coconut oil or butter.

  9. James says:

    Hi Dennis. What do you think about eating turkey as part of normal dietary consumption? Turkey has become quite popular in recent years as a meat alternative. Since it is poultry, is it different than eating chicken? Thanks.

    Thanks for your valuable insights on men’s health.

    • P. D. Mangan says:

      James, appreciate it. Turkey generally seems pretty healthy. With chicken, it’s the fat that mainly contributes to it being less than optimal, and turkey is less fatty. In this case, low fat is a good thing, since it means less polyunsaturated omega-6 fat. There may be some exceptions depending on the part of the bird being eaten, but I’d say go ahead and eat turkey.

  10. louis sir says:

    The problem with the chicken analysis is the varied fat content of different pieces. is there a breakdown of wings versus thigh versus breast?

    Chicken thighs/wings are tasty but they may be the source of all the O-6’s? And God knows what kind of oil your yummy buffalo wings are made out of (then again, butter is part of the classic buffalo sauce recipe).

    The boobies may be tasteless and lean so there may ultimately be less O-6’s?

  11. louis sir says:

    “made out of’ meaning “fried in”

  12. Mike says:

    Oils are oils with the exception of PUFA’s, of which too many contribute to weakened cells since they displace the sturdier, and more stable

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