Home » Articles » Ketosis – Are you “Looking for Purple”?

Ketosis – Are you “Looking for Purple”?

"Ketonuria" by Colin - Own work. Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Ketonuria.jpg#/media/File:Ketonuria.jpg

One question I’m asked a great deal is about what colour the “Ketostix (TM)” testing strips should be, and where to get them…

My answers are always this:

The concept of Benign Dietary Ketosis was championed by Dr Robert Atkins right from the start, when he published the first version of his plan in 1972. He mentions that you should measure your excreted ketones via urinalysis and be looking for a purple result.

Where to get Ketone Urinalysis sticks? Either, via Amazon (Pretty much the easiest option) or at the Pharmacy counter of any dispensing Chemist. They are a “P” grade medicine, so you have to ask for them.

(Note that Boots the Chemist have a corporate policy to refuse to sell them to Non-diabetics, “This is in the interests of a ‘healthy lifestyle'” (???). Some branches are reportedly not towing the company line (I suspect the ones that have low-carbers in the Pharmacy section) but most are… Either way, this is a good reason to support your local pharmacy.)

However, being in BDK is like being pregnant. You either are, or you aren’t. The colour is irrelevant, any shade of Pink/Purple will do.

If fact, purple may well be a sign that you are pushing too hard and eating too few vegetable based carbs, as purple means that you are dumping a great deal of excess ketones into urine, rather than burning them via body process. If you are “purple” but find that you are not dropping fat, your body may well be fighting against your mind’s want to drop your excess fast so that it can preserve its homoeostasis and keep you alive.

If you are following Dr Atkins’ plan and so testing regularly, the preferable colour really is a pale pink, as this is an indicator that your body is in its optimum fat burning zone, using everything that you are producing and not dumping any excess.

Once you are effectively burning body fat, most people can tell they are “in BDK” by the slightly metallic taste in their mouths. Some people say that their body odour changes (Not a BO odour, just personal smell) to incorporate metallic tinges, whilst others report that their urine has a more noticeable “healthy pee” smell. (Foul smelling urine is a sign of a UTI, go see a doctor immediately.)

However, there is another factor to consider in this, and it may well make you want to just save your money and not test at all.

Your body make two main ketone bodies. “Acetoacetic acid”and “Beta-Hydroxybutyric acid” (HBA).  Acetoacetic acid will spontaneously break down to form Acetone if it is not used by the body to fuel itself. Acetone is a waste product, it cannot be converted back into energy nor stored, it has to be excreted. Acetone is the compound which gives the faint, but distinct “sweet and fruity” smell on ones breath.

Ketostix, which are not cheap, only detect the Acetoacetic acid and Acetone. However, these make up less than one fifth of the ketone bodies produced when a body is effectively burning fat.

HBA goes totally undetected by Ketostix testing and many people never produce enough Acetoacetic acid to cause these sticks to turn pink/purple.

If you were to have your blood drawn however, you would have plenty of HBA kicking around in there. With a blood monitor, showing all three ketone type, a reading between 0.5 and 3.0 mmol/l is the indicator for nutritional ketosis.

This means that, whilst it may be interesting to use urinalysis as an initial check, but it will have nothing to do with your rate of body fat reduction.

I personally don’t think that Dr A did himself or us any favours by saying that you are aiming for Purple, my opinion is that he popped the testing in there to give a “rapid indicator result” support crutch to the people that want and need those fast result type indicators.

The body converts fat into ketones and burns these as fuel in preference to glucose right up to the 100g of non-processed carbs a day mark for most people and will only show ketones in urine at very low carb intake levels (i.e. the Atkins’ 20g induction level), where, if held that low for too long, insulin sensitivity can be increased so much that raising carb levels again can become problematic.

In my opinion, just eat right and save your money.

Leave a Reply