A study from 2013 suggests that the dreaded skinny-fat phenomenon – where a person is skinny but also flabby – may have a surprising cause: soybean oil.

The study shows that soybean oil heated for three hours increases fat tissue levels in rodents, while making them gain less weight than unheated soybean oil.

We’ve already written at length about some pretty terrifying studies of soybean oil, including one study that shows that it causes genetic dysregulation and brain damage to mice. These studies should be particularly concerning because soybean oil is the most widely consumed oil in the United States and is a ubiquitous ingredient in processed food, which we’ve dubbed “a food that makes you ugly“.

The dreaded skinny-fat body: is soybean oil the cause?

Soybean oil

The researchers were building on previous research concerning the effects of heavily oxidised fats on weight levels.

Four to six week old male C57BL/6 J mice were randomly divided into three groups and given either a low-fat diet with heated soybean oil (HSO) or unheated soybean oil (USO) or pair fed for 16 weeks. The heated soybean oil was heated for three hours.

Weight and food intake were monitored and fat pads were harvested upon the study’s termination. Mice consuming the HSO diet had significantly increased fat pad mass but gained less weight as compared to mice in the USO group despite a similar caloric intake and similar levels of PPARγ and UCP1.

The graph on the left shows that fat mass increased significantly in the mice fed heated soybean oil
This table shows that mice fed heated soybean oil gained less weight overall, despite gaining more fat mass

Basically, the evidence is saying that heated soybean oil is responsible for a shift towards fat storage, even though the weight gain is less. The potential implications of this are very interesting.

Given that soybean oil is the most widely consumed oil in the United States, then it’s entirely possible that this oil could be a cause of the dreaded skinny-fat phenomenon, which is now so pervasive throughout the developed world, and especially the US. A skinny-fat person is quite literally that: skinny, but also flabby. Just like Lucas of Lucas Room fame.

One objection to this proposition about soybean oil might be that people don’t usually consume soybean oil that’s been heated for three hours. Well, that’s not actually true. In fact, the reality is far worse. If you eat out regularly, it’s likely you’re eating soybean oil that’s been heated for much longer than that.

It’s worth remembering that even the cleanest restaurants will use the same oil in their fryers for a whole day, and the worst might take weeks or even months before they change their oil.

If you eat out in the “right” place, you might be eating food cooked in soybean oil that’s been heated for only 24 hours. But if you eat in the “wrong” place, the soybean oil may be older than Leonardo di Caprio’s latest girlfriend…

Don’t believe us? Take a look at the Quora answers below. Note that filtering just means removing solid particles from the oil.

We’ve already written a number of articles about why eating out regularly is bad for you and has been linked to an increased risk of all-cause mortality. As we note in our dieting bible, Dieting Done Right, which is available from Gumroad, restaurant food is usually far more calorific and less healthy than home-cooked equivalents, for a variety of reasons. The quality of the oil used – and by that we usually mean cheap vegetable oil like soybean – will also be a factor, as this new study highlights.

It shouldn’t be a surprise then that obesity levels track with the growth of eating out rather than preparing food at home. The US Department of Agriculture recently estimated that Americans’ daily energy intake from food from outside the home increased from 17% in 1977-1978 to 34% in 2011-2012. Over that same period, the number of restaurants increased significantly. 

On the subject of oxidation, it’s also worth saying that vegetable oils, including soybean oil, usually come heavily oxidized as-is and are prone to further oxidization due to age and exposure to sunlight and even normal room temperatures. So if you’re cooking with old soybean oil, you might as well be cooking with oil that’s been heated for hours.

Skinny-fat? Here’s what to do

If you suffer from the dreaded skinny-fat physique, we’ve got just the program for you!

Our Skinny-Fat Program is a tailor-made guide to help skinny-fat guys make necessary alterations to their lifestyle, diet, workouts, and more.

Within, we identify each causal factor of what causes somebody to become skinny-fat and outline a plan of action to tackle each — to help them achieve the body they crave. 

As we’ve said, a good workout program alone will not suffice in helping you sculpt the body you desire if you are skinny-fat.

A good workout program may enable you to familiarize yourself with the gym and part of the lifestyle changes necessary to undo a skinny-fat body.

Instead, a well-aimed plan of action that targets every aspect of life from diet, to sleep, to stress management, to supplementation, and a kickass workout program is just what the doctor ordered.

Our Skinny Fat: The Ultimate Recomp: From Sickly Weak to Sick Physique is a unique program to facilitate your recovery from being “skinny fat” to a veritable beast.

Click here to visit our Gumroad store, where you can buy the program now!

What’s the answer, then? We’ve already recommended avoiding all vegetable oils and we’ll issue that guidance again. If you go out, avoid deep-friend food and ask for pan-friend food to be cooked in healthy butter or olive oil. One foolproof way to do this is to say you have an allergy.

Don’t hesitate to email us at [email protected] for personalized coaching and a client questionnaire if you’d like DEDICATED tailor-made personal training on strength training, building muscle, losing fat, developing athleticism, and more — all to your liking, lifestyle, habits, and taste!

Otherwise, don’t forget to claim your FREE eBook detailing how to lose 20lb of fat while building muscle in 12 weeks! You can claim it here.

Alternatively, you can pick up a FREE eBook on fundamental strength principles offering an introductory workout program.