This week for some reason is turning into macronutrient week. I’ve been reading up on proteins and fats. The Good Fat Cookbook is half a pop-sci recap of science research on fats and the second half are recipes.
FYI, the answer is that the good (vegetarian) fats are coconut, nuts, butter, olive oil, avacado, eggs and dairy fat. The bad (vegetarian fats) are margarine, soy, canola, mostly on grounds of hydrogenation and transfats. The book is generally pro-animal fats, but I skipped most of the text on those. I’m a vegetarian on grounds other than health, so I’m not interested in parsing the arguments. In any case, the book has warnings against saturated animal fats on page 26-27.
Macronutrients are agricultural commodities and the popular science press is an avenue for agribusiness to promote or smear products to their own best interests, so I’m sceptical of a lot of this research. There has been a smear campaign against tropical oils such as coconuts and palm oil. All commodities fund research and promote their products and being healthy, heck even cigarettes did at one point. In any case, the epidimilogical research I’ve seen on consumption of animal products points towards disease.
There are some seeming noncontroversial facts. Transfats are bad. Transfats are created by hydrogenating oil or overheating oils. [Update: merely heating oils will not create enough transfats to be interesting, after if it was possible to hydrogenate oil with 10 minutes of stove top cooking, manufacturers would do so, but instead they have to bubble hydrogen through oil for an hour to hydrogenate it.]
There are only a few vegetarian solid non-transfat fats, namely palm kernel oil and coconut oil. The fact that SE Asians eat up to 100 coconuts a year and have better heart health outcomes than Americans is reassuring.
Olive oil appears to be a non-controversial good oil, but it goes rancid easily. Same for nut oils. In any case, all my gourmet cook books recommend using it and in general, I think olive oil works well in gourmet cooking, especially in recipes where you are likely to notice the oil, for example in a salad.
Soy and canola oil appear to be controversial. A key issue with, canola, plus many other oils, is the chemicals used to process them (which may be an environmental bad, even if not a single molecule of a nasty processing chemical remains in the final product), and the heat required to refine a vegetable oil. Plus, once a vegetable oil is refined, it has hardly any oder, even when rancid, so you don’t get a signal to avoid a stale oil. Some of these issues are addressed by using expeller pressed oils, which keep the temperatures low and use physical extraction methods instead of chemical methods. Also, like any oil, a chef needs to keep a keen eye on the freshness and expiration dates of an oil, since rancid oils don’t taste any good, and could be harmful to the health to boot.
Transfats and Canola. It seems refining the oils creates transfats. Exactly how that squares with my bottle of Whole Foods Canola oil that says 0 transfats, I’m not sure. Maybe the refiners have fixed their process to stop putting tranfats into the bottle. I skipped over to the Canadian Canola oil website (did you know Canola is short of Canadian Oil? Canola was first developed in Canada), where they claim canola is the lowest in saturated fat, has no transfats and no cholesterol. So I’m not entirely sure why Canola got a bad review in this book.
Omega-3 Fatty acids appear to be good at some optimal level. For vegetarians, you can get some from flax-seed, walnuts and less from soy and canola oil. (Although in the Good Fat Cookbook, both of these oils are deprecated) Remember though, that both walnut and flax oil spoil very easily. Also, flax seed will pass right through you if it isn’t ground up.
As for the percent of calories you should get from fat, The Good Fat Cookbook is on the higher range of recommendations. Personally, I think the optimal ratio has a lot to do with your specific genetics. I’ve eaten a fairly high carb diet most of my life (especially after becoming vegetarian) and in general, I have a hard time gaining weight. If you’re ancestors ate tonnes of saturated fat, then you will be able to as well, but if you ancestors got by on mostly oatmeal then saturated fat might just give you an early coronary heart attack.
Anyhow, while I don’t think this book changed my opinion much, I think I did learn more about ranking the subtypes of fats, after you have chosen which one you are brave enough to add to your diet.