In February of 2014, for reasons more or less related to anger and spite, I started to rewrite one of my books. What started as a rewrite rapidly went out of control as it morphed into a nearly 400 page tome on all aspects of fat loss.
At the roughly 85-90% completion mark, I realized that that book was missing a big section, a topic I had been avoiding for about a decade. That topic was women and fat loss.
I had known for some time that women had far more issues to contend with in men, gaining fat more readily and losing fat with more difficulty among them but, probably out of fear of the complexity, had put a long-promised project on hold.
But as I neared the conclusion of the other book, I realized that I couldn’t put it off any longer. It was time to delve into that topic. As I started to talk about it online, putting up small excerpts, it became clear that having that as only a single section of a larger project was misguided and that I should separate it out into a book only on women’s issues. Little did I know what I was getting myself into.
What I thought might take 100 pages or so rapidly spiraled out of control, every topic becoming more complex, detailed and nuanced the deeper I got into it. Originally intending the book to cover women’s issues in terms of diet, fat loss and training, I would decide to split it into two Volumes to keep the page length more manageable and help to get the book completed before the eventual heat death of the universe. That wouldn’t prevent Volume 1, on nutrition and fat loss from approaching and eventually exceeding 400 pages with over 26 pages of references.
Now, 2.5 years later, Volume 1 is actually nearing completion. I’m just past the halfway point on editing with roughly 200 pages done (as in done I won’t look at them again until the final stages). In an ideal world, it will be out before Christmas both for gift purposes and because female physique athletes will be starting their contest diets.
The book has morphed and changed endlessly over the past 2.5 years as I’ve re-organized, re-structured and/or added content. The finalized table of contents appears below and you can see that any topic that could be covered is covered. I’d mention that Eric Helms has not only contributed endless feedback on the book but also the first appendix on peak week and making weight. His input has been invaluable.
To give people a taste of the book, I’ve included an excerpt from Chapter 1 below.
Gender Differences: Introduction
Regardless of all of the above, it’s abundantly clear that there are distinct differences between men and women and they cut across nearly all domains including those covered in this book such as diet, nutrition and fat loss (exercise and training being covered in Volume 2). Let me state up front that the differences I will be discussing, especially many of the physical differences represent no more than averages. Usually researchers study a huge number of subjects and look at the average response. But an average response says nothing about any given individual and it’s trivial to find an exception to just about any topic I will discuss. For example, despite the fact that women are, on average, shorter than men, clearly you can find a woman who is taller than a man. Despite the fact that the average woman typically has narrower shoulders and wider hips than a man, you can find a woman with narrower hips and wider shoulders. As frequently as not the variation within a gender is actually greater than the difference between genders (3). And at least in some area, women may show even more variability than men.
Throughout most of this book when I address gender differences I will put it in terms of “Women show such and such of a difference compared to men.” and I want to address my choice of that phrasing. A recent book about the Chinese female Olympic Lifting team makes a fairly impassioned point that using men as the baseline for sports performance represents not only the history of the idea of men being inherent superior but an androcentric (male) viewpoint overall (4). That is, typically speaking, women are compared to men in terms of their physiology, biomechanics, response to training, etc. instead of the other way around. And strictly speaking it would make just as much sense to reverse it. For example, women tend to handle heat better than men (at least during some phases of the menstrual cycle) and it would be just as accurate to state that “Men handle heat worse than woman” as “Women handle heat better than men.” That said, when examining gender differences I will still discuss them in terms of a woman’s response relative to a man’s. There are three reasons for my choice in this.
The first is that is a book about women’s issues related to nutrition and fat loss. To describe differences in physiology in terms of men’s responses relative to women would make little sense since it is the woman’s response that is important The second is that, with one odd exception discussed above regarding dieting studies, staggeringly more research has been done on men relative women (even now research on men is done at about a 4:1 ratio to that on women). It’s only been fairly recently that women’s response, or explicit gender difference studies have become more common place. And since there is far more research on men, comparing women’s responses to men’s makes logical sense to me here.
Finally, and perhaps most importantly from a practical sense, the fact is that a majority of ideas about nutrition and fat loss that are applied to women typically come out of either research or practice on men. Since most athletes have traditionally been male, most coaches have as well. This is changing in modern times and there are more and more female coaches (usually coaching women) but many of the ideas and approaches to training, exercise, dieting and fat loss come out of male-oriented approaches which may not only be ineffective but damaging. Addressing that means comparing women to men to some degree.
A Snapshot of Gender Differences
In no particular order of importance, here is a brief look at a a few of the (again, average) differences between women and men. On average, women are lighter, with less lean body mass and more body-fat than men. They also carry their fat differently with a more lower-body fat patterning. Their bodies utilize protein, carbohydrates and fats differently than men both at rest, after a meal and during exercise. They regulate what is called energy homeostasis differently than men (ultimately sparing the loss of body fat).
Physically, women’s wider hips alter their knee biomechanics (predisposing them to certain kinds of injuries). Women tend to be more flexible with relatively more mobile tendons and joints. And while women’s muscles are physiologically identical to male’s for the most part, there are differences in how they generate force or fatigue in response to exercise. As I mentioned above, on average female athletes perform at a level roughly 10% below that of men in most sports (with two exceptions). While women typically start out with lower levels of fitness than men, they respond similarly if not identically in terms of the relative improvements that they make in response to training.
Perhaps the most major difference between women and men has to do with hormones, especially the existence of the menstrual cycle. Discussed in detail later in this book, this represents the roughly monthly cycle of hormonal variations that a woman undergoes (in contrast, a man’s hormones are relatively stable across the month). This changes her physiology at a fundamental level and introduces a complexity that simply isn’t seen in men. This can also be modified in a stunning number of ways with what I will call hormonal modifiers changing a woman’s physiology subtly or not so subtly.
The Cause of The Differences
This raises the next important question which is what the genesis of these differences is. Of some interest is the fact that most parts of a woman and man’s bodies are actually identical in a physical sense. Under a microscope, a woman’s bone is the same as a man’s bone in terms of it’s cellular structure, it’s just not as dense. A woman’s muscle is almost identical to a man’s in terms of it’s cellular structure, it’s just typically smaller (there are other small differences I won’t get into here). A woman’s heart, lungs, etc. are all identical in cellular structure (albeit smaller) with the largest physical difference arguably being in the genitalia. Of course there are clearly differences that appear in terms of the relative amounts of fat, muscle, etc. So if the underlying structures are more or less identical, why are these differences seen?
Whenever a fairly large scale difference between women and men shows up, it’s been traditional to assume that it is due to underlying genetic/chromosomal or hormonal differences. In recent years, the idea that all physical differences between women and men, especially the differences in strength or sports performance, are culturally generated is being more commonly heard. As usual, the truth lies between the two extremes. Certainly it would be absurd to dismiss the role of environment or society and culture on women’s, or for that matter anyone’s, overall nature. But it’s equally absurd to dismiss the differences between the sexes in terms of biology. And since this isn’t a book about society or culture, it is the biology that I will primarily focus on. Because not only are those changes significant, it’s actually the case that many of them are set in place before birth, before any social or cultural influences are present.
A woman and a man’s genetic code differs, readers may remember that woman have XX and men XY chromosomes which are a huge part of what “tells” the body how to develop (especially in terms of the reproductive organs). Related to this, in recent years there have been issues concerning women in sport and biological sex testing. As this topic has more to do with emotion and political agendas rather than biology or physiology at this point, I am not going to begin to touch it in this book
The Role of Hormones
Other than genetics and the difference in genitalia, arguably the largest biological difference between women and men is in the relative amounts of the primary reproductive hormones. In women, these are estrogen and progesterone and in men it is testosterone. Both sexes make all three hormones but the relatively amounts in adults differ significantly. On average women having roughly 1/10th to 1/30th the testosterone levels of men; men have similarly low levels of estrogen and progesterone. It would be patently absurd to pretend that this isn’t impacting on the physiology of a woman versus a man directly in addition to any interaction with aspects of her genetic programming.
A singular example is that women’s bodies genetically form more of what are called pre-adipocytes (think of these as baby fat cells) in their lower bodies. These pre-adipocytes are stimulated to become fully formed fat cells and this occurs under the impact of hormones estrogen and progesterone with estrogen specifically impacting on the development of lower body fat cells in women (5). Even that doesn’t occur until what might be described as one of the most profound times of life for both girls and boys occurs which is puberty. Prior to that, little girls and boys are more or less physically and physiologically identical. When there are differences they tend to be small and are generally in the same direction I mentioned above (i.e. girls are still slightly shorter or carry slightly more fat).
But it is at puberty, when the reproductive organs become active and hormonal levels diverge enormously that the primary physical and physiological differences between the sexes appear . A woman’s specific physiology develops under the effects of estrogen and progesterone as does a male’s under the influence of testosterone. Women develop their traditional body fat patterns, increasing not only total body fat but lower body fat specifically while men develop more muscle mass while losing fat. Effectively puberty is when the typical feminine and masculine physiologies develop and let me reiterate (for those who skipped the preface) that I am using these terms only as descriptive shorthand with no implication about whether or not one is a relatively more or less appropriate or superior gender role than the other. We all know what these terms refer to and it’s just easier writing it this way.
This is further shown by the fact that even small changes in hormones can have a profound impact. Even small changes in the levels of testosterone in women can drastically impact on her physiology, effectively masculinizing her in many ways (the effect is even more pronounced in women who use anabolic steroids, derivatives of testosterone).. I’ll talk about specific examples of this in later chapters and other factors that change or modify a woman’s overall hormonal profile drastically impact her physiology. Menopause is one of the most profound of those as through the process peri-menopause through the menopausal transition itself, her hormones drop from their youthful levels to nearly zero.
None of the above is meant to in any way dismiss the role of culture and environment in this. Clearly it plays a role and to ignore it is a mistake. When I talk about training and injury risk in Volume 2, I’ll talk about a very specific place where culture/environment (specifically women’s typically lower involvement in sport at a young age) interact with her biology in a profoundly negative way. For now I want to briefly discuss a topic I said I wasn’t going to talk about much in the preface.