The main thesis behind Why Women Need Fat (out this month from William Lassek, MD and Steven Gaulin, PhD of the University of Pittsburgh) is super fascinating and builds nicely on the Fat Trap business we were talking about yesterday: Your body fights weight loss tooth and nail because evolution has found fat to be quite handy in a survival of the species sort of way. So I went ahead and blogged about all of that on Never Say Diet.

But, full disclosure: I haven’t read the book yet. I’m still waiting to get a copy into my hot little hands, so I had to restrict my analysis to the unfortunate, red flag-waving subtitle (How “Healthy” Food Makes Us Gain Weight and the Surprising Solution to Losing It Forever — oh boy!) and, more encouragingly, the way Dr. Gaulin describes their research in this Salon.com interview.

So I’ll be back with a more in-depth post about the book itself once I, you know, read it. Ahem. Yes, tireless and thorough reporting is what you can expect around here.

In the meantime, let me clarify that I’m not blaming Gaulin or Lassek for the subtitle. My guess is that was the publisher’s doing, as part of their “now this is how you sell a book about evolutionary biology!” strategy. They’re probably not altogether wrong either. But it does put the researchers between a bit of a rock and a hard place because they are simultaneously trying to explain why we’re probably all supposed to be a bit fatter than the Beauty Trap (and the diet industry) allows — and yet also, that we’d all weigh less than we currently do if our diet wasn’t so heavy in highly processed omega-6 fatty acids or “bad fats.” (There’s another red flag.)

Depressingly, I guess that sounds about right: We chase an unrealistic standard of thinness (that has nothing to do with health) while ignoring the kind of basic healthy lifestyle choices that might result in a more attainable version of thinness — because we’d just reject that as not good enough. (Caveat: It also might not result in us getting any thinner and some of us would even gain weight — the link between lifestyle and weight being so much murkier and potentially less causal than we’ve been led to believe.)

This dichotomy is perhaps better illustrated by the “Your Natural Weight” chart on their website. At first I was annoyed, because the chart says, as a woman over 30 (I mean, by a hair, but anyway!) who weighs 157 pounds or thereabouts, my “natural weight” is really 20 pounds less. How is this any better than using the Body Mass Index scale? I thought. (In the Salon piece, Dr. Gaulin gives an excellent explanation of why BMI is a total fallacy, at least when it comes to women’s health.)

Well, Dr. Gaulin defines your “natural weight” as “how much you would have weighed if you had not experienced” the process-izing and Super-sizing of the American diet, which began 40 years ago. Except: Ever since leaving my Beauty U McDonald’s habit behind 18 months ago, I don’t eat the typical American omega-6-laden diet. And the only time in my adult life I have sustained my so-called “natural weight” of 137 (20 pounds less than where I am now) was for about five minutes during the year I ran two half-marathons. There were a lot of pros about that experience (stronger lungs! awesome endorphin rushes!) but it also resulted in a stress fracture and some fairly disordered body-related feelings. To say nothing of: 40 years ago, Americans did not spend all of their free time training to run long distances. Jogging was barely even a sport. If that’s what it takes to get to my “natural weight,” I’m not sure how “natural” that weight can really be.

So the “natural weight” concept has a few problems — namely, that it’s incredibly problematic to use weight as your main barometer of health, as we discussed yesterday. (The “natural weight” chart doesn’t factor in your gender, height, activity level, or any physical markers of health like blood pressure and cholesterol.) For all of the biological reasons discussed in the Fat Trap story, it’s entirely possible that my “natural weight” at this age/stage of my life is somewhere in the 150s, not the 130s, despite my willingness to generally avoid omega-6 fatty acids because they aren’t so good for my heart. Again, once I read the book, I’ll let you know if any of these questions are resolved. I will say one point in Gaulin & Lassek’s favor: I did gain 20 pounds when I adopted the more processed, fat-heavy diet in beauty school. So it’s also possible that my weight is still settling back down to “natural” on a healthier diet. Research published in The Lancet last year showed that when weight loss does work at all, it takes for-freaking-ever — think three years to lose 25 pounds.

But enough about my weight, because that’s so not the point here. When I looked back at the chart, I realized something kinda cool: It covers a big range of weights from “less than 130” to “250+” but suggests a much smaller range of weight loss. Someone weighing less than 130 needs to lose only 10 pounds to reach their so-called “natural weight” (I know, I know, does someone weighing less than 130 pounds ever need to lose weight? Unless she’s shooting a Vogue cover, probably not), while someone weighing 250+ needs to lose only 40 pounds. The goal is not to make everyone weigh a uniform 120 pounds, no matter what. 

So at the very least, I like that Why Women Need Fat explains why women do, in fact, need fat — and that it seems to subscribe to the idea that human beings come in a naturally occurring range of sizes, and that however unhealthy our processed diet may be, the solution is not to drop drastic amounts of weight to correct for that. In my perfect world, the solution would be to incorporate more healthy foods into your life and let the weight shake out where it may. There’s still that troubling subtitle to contend with, so I’m guessing that’s not quite where Gaulin and Lassek land… but a girl can dream!