In one of there podcasts they said to stay away from olive oil which has a lot of poly and mono saturates and have saturated fats in its place? Please can someone explain because it's gone against everything I've heard before.
The whole saturated=bad thing appears to be old junk science.
It appears now that monounsaturated fats are good, saturated fats are good when they come from high quality sources (most don't: grass-fed vs. grain-fed, hormones, antibiotics...), and that polyunsaturated fats are only healthy in small amounts. They tend to oxidize and go rancid. The short shelf-life is kind of a tell.
Also, with polyunsaturated fats, there seems to be an imbalance: A Modern diet contains way too much Omega-6 and too little Omega-3.
As for Olive Oil, these workoutmasters are probably wrong, though.
Olive oil is rich in monounsaturated fats, and while it does contain Omega-6 polyunsaturated fats, it is relatively low in them. This makes it the good kind of vegetable oil.
I've never seen anything pointing to monounsaturated fats being bad.
Looking beyond the macro, good olive oil contains some mighty beneficial micronutrients like polyphenols.
The bottom line with many of these recommendations is that they are based on observational studies. Observational studies are the precursors to performing a clinical study. A clinical study is what is used to determine the difference between causation and correlation. Causation is when one action directly causes a result. Correlation is merely when people are observed doing one thing, the result is also present.
For example, a heart attack can cause death. People who eat red meat correlate to having heart attacks. That does not mean that eating red meat causes heart attacks. There very well may be other factors at work such as the fact that the red meat eaters are smokers (which the link between smoking and heart attacks has been proven in a clinical study).
Bottom line is that you are going to have to make judgement calls based on the available information. Our bodies need fat.
The Lipid Theory is the basis for most people's perception of saturated fats. The bottom line is that it is founded on bad science. In short it's like the observational study was converted to law without ever going through clinical trials.
When looking "this is good, that is bad" style articles, look deeper into what about the item in question is bad. For example, not all "Extra Virgin" Olive Oils pass the bar for the "Extra Virgin" label. If that's what the concern is, I can understand.
The only advice I can give that is fairly sensible is to stay away from engineered fats like vegetable oil, particularly if they happen to be high in trans fats.