One of the standard questions that comes up when discussing ketogenic nutrition with people considering starting on a low-carb/ketogenic diet is, “Do I need to buy the magic pee sticks if I want to do a ketogenic diet?”
The answer is usually, “It depends.” If you are limiting your carb intake to less than 20g/day, as outlined in the back of Why We Get Fat, then there’s really no need for them in the long term because if you maintain <20g of carbs a day, you’ll be in ketosis (with very few exceptions).
On the other hand, if you are trying a higher carb diet, such as paleo or primal, and want to know if the carb intake level you are shooting for is inducing ketosis, then you should probably pick up some ketostix and test yourself for a couple weeks as your body acclimates to your new way of eating. But even this is not strictly necessary. There are other ways to determine whether or not you are in ketosis. You might, for example, try exhaling into the face of a colleague or spouse. Through years of research, I have discovered that the more violent the reaction this invokes, the more likely it is that you are in ketosis.
Even though they are not strictly necessary, more often than not I suggest that if you’re starting on a new diet where ketosis comes into play, go buy some magic pee sticks and test daily (in the morning, after getting up) when you start. This can be an affirmation that your body is changing in response to the types of food you put in it, and can be some strong positive reinforcement as you work through the stress and anxiety that any lifestyle change as profound as a ketogenic diet is bound to produce. It can also clue you in to the effect that the inevitable screw up will have on your state of ketosis. This can be of great benefit as you find your way around your new food choices, and may help you detect slipups that might otherwise go unnoticed.
So, to answer the question: No they are not necessary, but you might want to use them anyways…especially in the beginning.
Where can I buy them?
In the US, you can purchase ketostix at just about any pharmacy. Often they are kept behind the counter, so you may have to ask the pharmacist for them.
Which brands should I use?
I’m familiar with two brands (though there are others). The most common brand I’ve seen is the Ketostix brand by Bayer. They come in a yellow package and in my area, run $12-$14 for a package of 50.
There’s also the Walmart brand, called “ReliOn Ketone Test Strips“. These are made by Bayer and in my experience, are identical to their higher-priced counterparts in every respect except the name on and color of the label. Oh yeah, there’s one more difference: they are usually half the price ($6.50-ish) of the name brand ones.
I’ll let you guess which ones I buy.