good fats

[colby2152]

What exactly are good fats? Is that the difference between unsaturated and trans fats, or is the definition based on where the fats come from (i.e. fish/poultry, etc..)???

 

[precious_roy]

Oh boy, some of this may not be correct, but I am going from OChem memory of 3 years ago (has it been that long?)

Basically, a fat (or tryglyceride) is a molecule that contains more than 1 fatty acid "linked" together. A fatty acid is a long chain that contains many carbon-hydrogen bonds. When all carbons are bonded to a hydrogen, the fatty acid is saturated. If there is some site where a carbon is not bonded to a hydrogen (ie there is a carbon-carbon double bond), then the fatty acid is unsaturated. If only a single unsaturated site is present, it is monounsaturated. If multiple sites, polyunsaturated.

When the fat is in your body, enzymes, called lipases, break down the fat into fatty acids for energy in a process called lipolysis. Your body can produce fatty acids from other components (sugar etc) and will under conditions of caloric surplus. However, there are certain types of fatty acids (commonly called omega-3 and omega-6) that your body cannot produce and so they must be consumed (kind of like essential amino acids).

If you take an unsaturated fat and heat it up really good with a catalyst and hydrogen, you can break one of the bonds from a non-hydrogen site and add a hydrogen to it. This is called "partially hydrogenating" and produces partially hydrogenated oils. Not only does it saturate the fat, it also alters the isomer of the fat from a "cis" to a "trans". The problem with this is the lipases cannot break down a "trans" fat, so this fat can impair blood flow (?).

As to why saturated fats are bad, I am not so sure on this one. Unsaturated fats are obviously needed by your body, and saturated fats maybe less so. Also, saturated fats can be turned by your body into cholesterol, which can be bad. You still should eat saturated fats, just limit them. My whole philosophy is dont eat in excess what your body doesn't need.

 

[colby2152]

Wow that was awesome precious_roy. A simple chemistry lesson may help me finally understand the difference between the different kind of fats...

Quote[/b] ]Unsaturated fats are obviously needed by your body, and saturated fats maybe less so.

What are the best foods that provide unsaturated fat?

Quote[/b] ]However, there are certain types of fatty acids (commonly called omega-3 and omega-6) that your body cannot produce and so they must be consumed (kind of like essential amino acids).

Also, what foods if any can I get the essential fatty acids (EFA's) from since supplements would be expensive?

Thanks,
Colby

 

[Old and Grey]

Bad fats make bad food taste good.

 

[Bryan Haycock]

Basically the only fat that is really saturated is animal fat. Coconuts might be an exception, but in general, beef fat and dairy fat are the real culprits when it comes to bad fats. Not to forge the food industry that turns unsaturated fet into saturated fat using a process called hydrogenation. Ever heard fo partially hydrogenated fat? That's just evil speak for saturated fat. Oh yeah, they make trans fat as well. Trans fats are probably worse than saturated fats.

Most essential fatty acids are present in high amounts in ordinary vegetable-based foods and food ingredients accept for omega-3 fats. So, if I were to try to adjust my diet in order to get more good fats, I would focus on omega-3s.

Fish, walnuts, and flax are good sources of omega-3s.

 

[precious_roy]

Quote[/b] ]What are the best foods that provide unsaturated fat?

All you have to do is look at the nutrition information on an item. It will give you grams of fat, as well as grams of saturated fat. Sometimes, if youre lucky, it will also give you the breakdown of poly and mono unsaturated fat. But in general (possibly sans trans fats, Im not sure) if you take the total grams of fat, and subtract off the grams of saturated fat, you get grams of unsaturated fat.

Brian is correct: most saturated fats come from animal sources. Not sure why this is; could be the fact that fat cells tend to store saturated fats? No idea. But there are many web pages that list the nutritional facts of stuff that doesnt have labels like a nice juicy tbone (not so appealing to me being a vegitarian, but whatever floats your boat).

Quote[/b] ]Also, what foods if any can I get the essential fatty acids (EFA's) from since supplements would be expensive?

Actually, cost wise, it is sometimes cheeper to purchase the supplements than to attempt to significantly alter your diet. A bottle of fish or flax seed oil can last a month or so and only costs about 8 bucks.

But naturally, like I said above, just read the nutritional labels. I filter foods as follows: if the ratio of unsaturated fat to saturated fat is greater than 2:1, Ill take that. Unless its like 20:10, then Ill just avoid that 30 grams of fat altogether. It depends on your diet though. Fish seems to be a great source, but again, I dont eat meat so I am not the best person to ask. Another cheep natural source is virgin olive oil (or extra virgin, for those who are Catholic...hehe). I think the ratio is like 13:1. A little meal for me is just to cook up some whole wheat angel hair pasta and add a tablespoon or two of olive oil. Good carbs and fat.

And yes, just try and avoid trans fats altogether if possible. They are in no way good for you. ALERT: If something says that it has 0g trans fat, it may still have trans fat! If you read through the ingredients and it says that it has "partially hydrogenated soybean or cottonseed oil", it has some amount of trans fats. Just FYI.

 

[BoSox]

less than a gram of trans fat is really nothing to lose sleep over.