Edit to answer: Fish oils are not trans fats. But my point was that you had not yet even run an n=1 experiment and shouldn't draw any conclusions from your experience (unless you think the weight loss and other changes you speak of would have no impact on your blood work...).
My problem is that I know a lot of this stuff but I don't really live it. Hard to change habits once you have developed them. I just love bread and pasta too much e.g.
For me, I love BBQ. I love Mexican. I hate cooking, so getting a crockpot and cooking mexican dishes (eg: chicken, taco seasoning, salsa and a little bit of peppers, plus 6 hours and you've got great tasting shredded chicken).... I don't feel like I've given up much. It does take a week or two to transition, though, and control over your diet (eating out is tough unless you go to BBQ restaurants.)
Trans fat is a fat that has hydrogens next to double bonds on both sides of the carbon chain. The natural trans fats that sometimes occur in beef and milk have been shown to possibly have a positive effect on LDL.
The main source of trans fat in the modern diet has been through artificially created trans fat made in a process using high heat and a catalyst like nickel to rearrange the bonds. Partially hydrogenated fats are ones where not all the hydrogen bonds are saturated, and are technically cis fats.
They did a six year study with monkeys, using fat as a control in the diet. One group ate trans fat, the other saturated: http://www.wakehealth.edu/News-Releases/2006/Trans_Fat_Leads...
Fish oil is not a trans fat. As far as a government boogeymen go, you may be confusing the research done in the late seventies that led to government recommendations against consuming saturated fats. You can read more about that, trans, and cis fats here: http://chemwiki.ucdavis.edu/Biological_Chemistry/Lipids/Fatt...
Also I tried looking this up and failed. But I'm sure that leptin wasn't discovered until the war on fat was well underway. And the first instinct when it was discovered was to try to use it as a drug target (all these failed badly).
The biggest problem is we have rejected science from food to begin with. We have government spending billions pushing a diet designed to create obesity (which is very high in carbs, effectively sugar, and low in fat.)
Likely there are at least two types of people biochemically- those who are insulin sensitive and those who are insulin resistant.
The insulin sensitive tend to not be fat and if they are fat its because they are really over eating. These people are the ones who end up thinking that fat people are lazy, or who think that "You should just eat less sugar" (not realizing that carbs are effectively sugar) or "calories in < calories out".
The insulin resistant people tend to be the fat ones. And for them a diet low in carbs is effective. I've seen a lot of studies and this is consistent in all of them.
Personally, I finally found out about the effect insulin plays on the creation and storage of energy in fat cells.
Government has been pushing a high carb diet for decades and as at the same time we have an obesity epidemic. Instead of recognizing the problem (correlation is not causation but you can't claim they have caused obesity to go down) they are going to war against fats. Transfats being banned is junk science (I eat a lot of them and my blood work is great, and getting better, not worse) and their use in the food system is because of government going to war on "Saturated" fats in the first place.
The war on Fat is the cause of obesity, in my opinion, because it is political, and not scientific, and ignores the insulin sensitivity issue.
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I'm slow banned because this site is not tolerant of diversity, so I can't reply to Max below. (And so I'm off to do something fun. Caio!)
Here's the reply I tried to give him:
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Fish oil is trans fats. I'm taking trans fats supplements!
I think the larger issue is that people are looking at things way too simplistically ("trans fats bad because more of them means problem x") and not controlling for other things-- eg: there's a huge difference between eating a pure meat and vegetable diet (And consequently a lot of fat) and eating a lot of fats in the presence of a lot of carbs. Those anti-trans fats studies did not control for carbs (as far as I can tell).
This is why the blood work of people on keto disproves the "trans fats bad" hypothesis.
And also "trans fats" are a government propaganda boogeyman-- how many people take fish oil supplements and also oppose trans fats, do you think?
I can't do two experiments on myself at once. Since things are going in the right direction now, I want to enhance my weight loss.