Body fat part 1: An introduction

Body fat.

The words can send otherwise rational women into fits of paranoia and hushed, ashamed discussion of their failures. Years ago, I asked for a fitness assessment at my university gym. They offered a “lifestyle management package” which would measure body fat and fitness levels, offer nutritional counselling, and suggest an exercise program. Since I was already training and eating my veggies, all I really wanted to know was my body fat. I asked if this was possible. The woman behind the counter gave me a shocked look which was faintly admiring. “Wow”, she breathed, “You’re really brave.”

I gave her a puzzled smile. “It’s just a number”, I said. She widened her eyes at this brazen display of sangfroid.

Then I met with the woman who did the “lifestyle management” assessment, and explained to her that I just wanted my body fat measured. “We don’t really do that on its own”, she said.

This seemed confusing to me. Upon inquiry she explained that they avoided doing body fat assessments in isolation from nutritional and lifestyle counseling. A noble goal, of course, but one which was a bit frustrating to someone who just wanted a number. Asking to know my body fat was treated with the same quiet horror as a request to stuff and bronze my husband upon his demise. I pestered her until she begrudgingly said she would call the person who did the assessment and get back to me. Of course she never did. My theory is that the university calipers were in a bulletproof glass case, the two keys to which were hung around the neck of an army general and the President of the Yewnited States, played of course by Harrison Ford and not that weasely Ben Affleck (why a US president if this was Canadian? indulge this image, if you will, Tom Clancy fans).

What is it about body fat that inspires such fear and loathing? Fat is associated in our culture with undesirable qualities, particularly for women (I saw a guy at my gym the other day wearing a t-shirt that said, “It’s not a beer belly, it’s a gas tank for a sex machine”; imagine women wearing something comparable). Body fat, or at least the reduction of it through supplementation, diet, exercise, and surgery, is also a big industry. At this point, any discussion of body fat is not only rife with cultural anxieties, but also misconceptions and half-truths.

So, dear readers, since you know I never shy away from laying it on you with forthrightness and painful honesty, let’s talk about fat. Before you read any further, though it might be helpful for you to say that dirty f-word (no, not feminism) a few times to relieve it of its power to frighten you. Fat. Fat. Fat. Fatfatfatfatfatfaaaaat!

what is body fat?

Fat is a form of body tissue composed of cells which primarily store lipids (fatty acids and related compounds). These cells are embedded in a matrix of connective tissue. Fat cannot become muscle, and muscle cannot become fat, any more than your leg can become your arm. They are two entirely different types of tissues.

There are two types of fat tissue: brown adipose tissue (BAT) and white adipose tissue. Humans, unlike many other mammalian species who hibernate and/or require the specialized body temperature regulation that BAT provides, have mostly white adipose tissue (this is one reason why it’s hard to generalize animal data to humans).

Fat has many purposes: insulation, cushioning, fuel stores, and a source of estrogen production. Contrary to what you might think, your body does not have body fat because it’s trying to ruin your life. Rather, your body has fat because it’s trying to keep you alive as long as possible. Because of its composition, fat is an excellent and energy-efficient fuel source.

In general, we have a certain number of fat cells which remain more or less constant throughout our adult lives, if we maintain a roughly ideal weight for the duration. However, fat cells can also multiply if the body decides there is a need for them (for example, if you eat many more calories than your body can immediately use, over a long period of time, especially as a child), and then once you have them, they usually don’t go away unless you physically remove them (i.e. through a process such as liposuction). There is a process known as apoptosis, or “cell death”, which does occur with the administration of particular substances, or with illnesses such as HIV. However, at the moment, the bulk of the research has been performed on animals, so we cannot yet apply this to healthy humans who just want their fat cells to drop dead already so they can fit into that ugly bridesmaid’s dress by June.

Fat cells are kind of like little balloons that can be inflated or deflated (and they actually look sort of like a bunch of little balloons all squished together by connective tissue). When fat is “lost”, the little balloons just deflate, but they’re still there. “Cellulite”, by the way, is not a special kind of fat, but merely an effect of the fat’s position with regard to the connective tissue, and this depends largely on where the fat is, as well as age, gender, and genetics. Treatments that claim to reduce cellulite achieve a temporary tightening of the skin which gives the appearance of cellulite reduction for a brief time. As far as I’m concerned, “cellulite” is a word invented by an industry that has created a “problem” and wants to make money off the “solution” (notice that the word “cellulite” is usually accompanied by words like “revolutionary product” and “targeted fitness program” and “easy payments of only $19.95”).

In Part 2 of this article, I explain more about how gaining and losing body fat works.