If I limit saturated fats, do I need to worry about total fat?

Q.  I understand that fat should be limited in one's diet. However, I also understand that it's the saturated fats that are worst. Would it make sense to limit the saturated fats and not the total fat in the foods one eats?

A. Let's start with the "official" answer and then we'll dig a bit deeper.

The National Academy of Sciences (which sets the government's official dietary recommendations) suggests that you limit your saturated fat intake to 10% or less of your total calories and avoid trans fats entirely.  In addition, they also recommend limiting total fat to no more than 35% of all your calories.   

One reason to limit your consumption of fat is that eating a lot of high-fat foods--even when they contain "healthy" fats--can seduce you into eating more calories than you otherwise would, or should.  Fats are very calorie-dense but not particularly satiating, meaning that you can consume a whole heck of a lot of fat calories before you start to feel full.

But if you are eating the appropriate number of calories and otherwise getting all the nutrients you need, I think its possible to push the fat ratio a little higher and still have a very healthy diet.  A Mediterranean diet, for example, emphasizing fruits, vegetables, whole grains, fish, nuts, and olive oil has been shown to be extremely healthful, and may contain up to 50% of the calories from fats (mostly monounsaturated).

Now let's muddy the water even further:  Many readers of this blog would argue that there is no need to limit saturated fats because it's carbs that cause heart disease, not saturated fat. See, for example, the lively conversation going on on this post about eggs.   

I think the important principle here is you can't draw conclusions about the effects of individual dietary components, such as saturated fat, without taking into consideration the composition of the rest of the diet.

There is certainly a lot of evidence suggesting that a diet high in saturated fats can be quite healthy, providing that it is also very low in refined carbohydrates. On the other hand, a diet high in both saturated fats and refined carbohydrates is a pretty bad idea.  So, how much (and what kind of) fat your body will thrive on depends on your genetics and, even more importantly, how the rest of your diet looks.

One last twist: we've talked about saturated fats, trans fats, and monounsaturated fat, but haven't yet mentioned polyunsaturated fats (PUFAs).  You need a small amount of PUFAs in your diet because they supply essential fatty acids that you cannot get from any other source. These include the notorious omega-3 and omega-6 fats. 

It's very important to strike a balance between omega-6 and omega-3 fats. Most of us get a whole lot of omega-6 PUFAs (which are found in cereal grains, seeds, and vegetable oils) and not enough omega-3 PUFAs (which are found in fish, hemp, chia, and flaxseeds).   The resulting imbalance can lead to chronic inflammation, which increases your risk of many diseases. 

You read an awful lot about the importance of adding more omega-3 to your diet.  But there's another option that I don't see talked about much: reduce your consumption of omega 6!  When the two are in balance, you don't really need very much of either; a couple of grams per day is sufficient.  If you analyze your diet using ND's tracking tools, you'll see total omega-6 and omega-3 amounts (along with totals for saturated, trans, and monounsaturated fats) listed as part of the analysis report.