“It’s All Just Water”

This is the first in what I hope will be a continuing series of dumb things people say about the low-carb lifestyle.

I’ve been a firm believer in carbohydrate restriction for weight control and health maintenance since 2002, and in that time, I’ve heard a lot of really dumb things about low-carb, usually published in the media and spread about by people who think that, to borrow a phrase from “Yes, Virginia, there is a Santa Claus,” if you read it in The Sun, it must be true.

Because I truly believe that a lot of my readers could benefit from restricting their own carb consumption, I would like to debunk some of these ideas.  I’ll start with the idea that low-carb is a bad idea because the weight loss is all (or even mostly) water.    It is certainly true, as any low-carber knows, that you do lose some water in the first days of carb restriction.  But the notion that low-carbing is bad because “it’s all just water” rests on three assumptions that are untenable:

1. You only lose a little bit of weight by reducing your carbs.
2. Low-carb is a “diet” in the usual sense, which means that people go off the diet when they reach their weight loss goal.
3. It’s bad to lose water.

Let’s take these one at a time.

1.  You only lose a little bit of weight by reducing your carbs.  This assumption is plainly unwarranted, as there are numerous people who have lost 20, 40, or more pounds by giving up sugar and starch.  Jimmy Moore, at Livin’ La Vida Low-Carb, has lost 180 pounds.  I grant that it’s possible that someone who has only 5 or 10 pounds to lose could be shedding nothing but water, or mostly water.  But losing 180 pounds of water?  That’s 22.5 gallons of water!  That’s equal to 4 and a half of those gigantic bottles of water they put in water coolers.  If Jimmy Moore lost 22.5 gallons of water, all I can say is that he must be very glad to be rid of it.

2.  Low-carb is a “diet” in the usual sense, which means that people go off the diet when they reach their weight loss goal.  In other words, the assumption here is that, after you’ve lost all your weight, you will go back to your old way of eating and regain the water you lost.  I won’t deny that some people abuse low-carb lifestyles in this way – reducing their carbs until they reach a certain goal, then going right back to having bagels for breakfast every day.  But many, many people whose lives have been made miserable by sugar and starch know that once the weight is off and their health has improved, they need to continue restricting their carbs to maintain that result.  If excessive carbs make us fat and unhealthy, and reducing carbs makes us lean and healthy, why would we ever go back to eating large amounts of sugar and starch?  This is why I’ve stopped referring to low-carb as a diet and started calling it a lifestyle.

3.  It’s bad to lose water.  I blame this one on the “Get 8 or More Glasses of Water a Day” people.  Because of this bit of “wisdom,” which is effectively skewered at Snopes.com, by the way, our fear of becoming dehydrated has become almost hysterical.  If we’re all in danger of chronic dehydration, the initial water loss induced by carb restriction must be bad, because we are losing precious water!  But what if, on the contrary, the water lost is water we should be glad to shed?  As it turns out, this is exactly the case.  Insulin, the hormone that is produced when we eat carbohydrates, has effects on the body other than its role in carb metabolism.  It also causes our kidneys to retain sodium.  Here is just one of the many, many references you can find to this online:  http://ndt.oxfordjournals.org/cgi/content/abstract/14/10/2357, which says “Insulin induces sodium retention by increasing distal tubular sodium reabsorption.”  (Translation:  insulin causes your kidneys to hold onto sodium.)  And sodium retention, in turn, causes your body to hold onto excess water, because it needs to dilute the concentration of sodium in your tissues.  One of the results of excess water retention is – high blood pressure.    Getting rid of the excess sodium, and therefore the excess water, helps lower blood pressure.  This is why patients with high-blood pressure are often given diuretics, drugs that increase the excretion of fluid.  This also helps explain why blood pressure normalizes very quickly on low-carbohydrate regimens, and many low-carbers are able to stop or reduce their blood pressure medications (on a doctor’s advice, of course).

So the next time someone tells that low-carb weight loss is all water and that you’ll just regain it all when you go back to eating “normally,” ask them if they think that anyone could possibly lose 5, 8, or 22.5 gallons of water.  Ask them why they think you’re going to go back to eating “normally.”  And above all, ask them why think it’s such a bad thing to lose the excess water that’s causing your blood pressure to rise.