Wayne Westcott, PhD. in this article says the following:
Good grief! News flash!!! Calorie reduction makes you lose...muscle, not just fat. But should this worry us at all? After all, the number on the scale is still lower. And as we all know, the scale has the final word. Or not, as this article points out:
The most popular and straightforward way to produce a negative calorie balance is to diet. Eating 500 fewer calories per day results in a pound of fat loss per week. Still, even though dieting works reasonably well as a weight loss strategy, it has serious drawbacks.
Here’s one of them. When we reduce our calorie consumption most of the additional energy comes from stored fat, however, some of the additional energy comes from protein stores which results in muscle loss. Very low calorie diets (600-900 calories per day) may produce almost as much muscle loss as fat loss, which generates an additional problem. The reduction in muscle mass causes a corresponding decrease in metabolic rate, making further fat loss even more difficult.
This brings us to the scale's sneakiest attribute. It doesn't just weigh fat. It weighs muscle, bone, water, internal organs and all. When you lose "weight," that doesn't necessarily mean that you've lost fat. In fact, the scale has no way of telling you what you've lost (or gained). Losing muscle is nothing to celebrate. Muscle is a metabolically active tissue. The more muscle you have the more calories your body burns, even when you're just sitting around. That's one reason why a fit, active person is able to eat considerably more food than the dieter who is unwittingly destroying muscle tissue.Reminds me of the fat slim girl I once knew. It was me. My thyroid went out of whack a few months after the birth of my first child. I was losing weight steadily and of course very happy about that. I wasn't eating any more or less than usual, but I was breastfeeding and assumed that that was why my weight loss seemed so unusually effortless. Despite weight loss, heart palpitations, and easy bowel movements (you can feed me on a steady diet of prunes and I can still be constipated), it wasn't until the day when I noticed how my hand was shaking as I wrote out a deposit slip at the bank (yes, children, there was a time when you had to do strange things like that) that I realized that something was seriously wrong.
Robin Landis, author of "Body Fueling," compares fat and muscles to feathers and gold. One pound of fat is like a big fluffy, lumpy bunch of feathers, and one pound of muscle is small and valuable like a piece of gold. Obviously, you want to lose the dumpy, bulky feathers and keep the sleek beautiful gold. The problem with the scale is that it doesn't differentiate between the two. It can't tell you how much of your total body weight is lean tissue and how much is fat. There are several other measuring techniques that can accomplish this, although they vary in convenience, accuracy, and cost [...] The best measurement tool of all turns out to be your very own eyes. How do you look? How do you feel? How do your clothes fit? Are your rings looser? Do your muscles feel firmer? These are the true measurements of success. If you are exercising and eating right, don't be discouraged by a small gain on the scale.
I immediately went to the doctor, tests were done and Grave's disease was diagnosed. My thyroid was hyperactive. The endrocrinologist explained that my weight loss was actually muscle loss. With a simple test, he showed me how physically weak I had become. My thrilling weight loss was a mirage. As soon as I went on medication, my body started rebuilding muscle and the weight went back up.
Let's go back to the above quote and concentrate on the following statement: Losing muscle is nothing to celebrate. Muscle is a metabolically active tissue. The more muscle you have the more calories your body burns, even when you're just sitting around.
The more muscle you have, the more calories you burn, the more fat you lose. So going on a severely calorie-restricted diet, in particular if it doesn't have a significant exercise component, is a self-defeating proposition. I'll get back to the exercise in a minute, because this too is much more complicated than it may seem at first glance. But first, let's go on to further bad news: women have a naturally higher fat to muscle ratio than men. See this article. Fat is normal and necessary to a woman's fertility. Indeed, many elite women athletes as well as fashion models, who both carry very little fat on their bodies, often lose their periods and have fertility problems. Yes, there are also fertility problems associated with obesity, but often overweight and fertility issues come together as partner symptoms of polycystic ovarian syndrome (another story completely).
So from the starting gate, women are disadvantaged in the weight loss sweepstakes as compared to men in that they naturally carry more fat than their Y-chromosomed friends. And then, to add insult to injury, women seem to be prone to going on crazy diets based on severe caloric limitation, lose even more muscle and have even more trouble losing weight and what is even more important, maintaining weight loss.
So what's a woman to do?
As I see it, there truly is no simple answer although the first thing is probably to stop extreme dieting. It just doesn't work in the long run and in fact works against the possibility of sustainable weight loss, due to muscle loss and a slow-down of one's metabolism.
This article, published in The Journal of the American College of Nutrition starts by citing two studies that show that "Weight loss through dieting alone has been shown to result in a dramatic and sustained reduction in resting metabolism." The first article cited reports a drop of 22% in RMR [resting metabolic rate]. The second article's conclusion is chilling:
Maintenance of a reduced or elevated body weight is associated with compensatory changes in energy expenditure, which oppose the maintenance of a body weight that is different from the usual weight. These compensatory changes may account for the poor long-term efficacy of treatments for obesity.
Coming back to the initial article, it concludes that:
In summary, the addition of high volume aggressive resistance training to a VLCD was associated with a significant weight loss while preserving LBW and RMR. The preservation of LBW and RMR during the consumption of a VLCD did not occur with a standard treatment control aerobic training program. These results indicate that high volume resistance training may be beneficial for patients who use a VLCD to lose large amounts of weight at least for periods up to 12 weeks. Future clinical studies need to determine its efficacy in long term weight loss programs and the maintenance of this weight loss for extended periods of time.In other words, a person must engage in more than aerobic exercise to preserve LBW (lean body weight) and stop the RMR (resting metabolic rate) from dropping. The study showed that "high volume, aggressive resistance training was necessary, especially for people on a very low calorie diets (VLCD) in order to maintain FFM (fat free mass) and keep their metabolism from falling.
I would say that one of the most important things I've learned since starting to reflect on food, nutrition, and weight loss/gain/maintenance is the central role of exercise--and more specifically weight training. I would encourage everyone to find exercise that works for them and certainly do not want to discourage anyone from aerobic exercise. But I think the jury is definitely in when it comes to weight loss and exercise: weight training should definitely take centre stage IF and ONLY IF you can take your eyes off the scale and concentrate on building more muscle. Yes, dress/pants size counts...perhaps a lot more than we want to accept.
Gratitude statement: I am grateful to have met Fayrohz; very, very grateful.