Vaping, e-cigarettes and ketosis: how is it going?

For those not familiar, an electronic cigarette (e-cig or e-cigarette), personal vaporizer (PV) or electronic nicotine delivery system (ENDS) is a battery-powered vaporizer which simulates the feeling of smoking, but without combustion, commonly called “vaping”. The user automatically activates the e-cigarette by taking a puff, other devices turn on by pressing a button manually and they come in many variations, some even look like traditional cigarettes.  Instead of cigarette smoke, the user inhales the substance, commonly called vapor. E-cigarettes typically have a heating element that atomizes a liquid solution known as e-liquid.

Vaporizers have been around in various forms since the 1960s, though, in that era the sets were more of the tabletop variety and not very pocketable. Chinese pharmacist Han Lik is largely credited as the modern vaporizer’s inventor (also called “e-cigarettes”), apparently finding the inspiration after his father died from cancer. The device, then known as Ruyan (means “like smoke”) was a hit in his homeland, so naturally it made its way to the US in the mid 2000s. “Vaping” (the common term for using a vaporizer) is simply applying heat to a liquid which creates vapor. Breathing in the nearly-odorless vapor gives the smoker their nicotine hit. While the most common e-cigarettes look like traditional smokes and are often sold in ciggy-like packaging, the market is overflowing with variety.


Well, if you’re a smoker and tired of the aggro you get from the world around you — plus mom and dad’s special kind of grief — this gives you another avenue to get your nicotine fix. Also, the likelihood of your city/state/country already having banned tobacco use in public places is getting higher by the day, so simply finding a place to have a smoke is becoming a hassle. Next, consider the financials of smoking: yours truly was spending about $9.50 per day on smoking. Over the course of a year that shakes out to about $3,500. E-cigs are much less expensive: using various online calculators we see prices at about a third the cost per year. Prices will vary based on your habits, naturally.

If you’re a non smoker who despises smokers, there’s an added win for you, too. Consider that vaping isn’t like traditional smoking: there’s no smoke, and it really doesn’t smell bad at all. You can walk past or through a vape cloud and not smell a thing. Gone are your days as a smoker hater of having to roll your eyes and cough as you walk past smokers. Win, win, right?

E-liquids usually contain propylene glycol, vegetable glycerin, water, nicotine, and (lots of) flavorings and here comes the doubts: vaporizing will make me absorb calories? Is this intake sufficient to kick me out of ketosis? Let’s see the details.


YES there are calories on the e-juices. It is a continual source of amusement to me that people actually think that sugar and calories that get to your blood stream via absorption other than the stomach don’t have calories (also, technically the juice that condenses in your mouth you might end up ingesting). Sorry to say, if it gets to your blood stream and it has calories, it doesn’t make the slightest bit of difference how it got there. Substances that are inhaled into the lungs adhere to the lining of the oral mucosa through which they enter directly into the bloodstream. Inhaled substances are usually first changed into a gaseous form by igniting or volatilizing by intense heat. The lungs offer a large surface area through which the gaseous form may quickly pass directly into the bloodstream. Once a substance enters the bloodstream, it is transported throughout the body to various organ systems, including the brain. Substances that enter the liver may be metabolized there. Substances that enter the kidney may be excreted.

Although glycerine is a carbohydrate, it has a different metabolic effect on the body. Unlike typical carbohydrates, glycerine reportedly has minimal impact on blood sugar levels. You should still count the calories (4.3 calories per gram) you are consuming from this product, since even a low carbohydrate diet needs some calorie control, but you do not need to worry about disrupting ketosis because there is no evidence that glycerine effects blood sugar, which is the way that normal carbohydrates disrupt ketosis.


Vegetable Glycerin (VG) Explained
Glycerin, also known as Glycerol, is an organic compound of carbon, hydrogen and oxygenwith the chemical formula C3H8O3. It is produced industrially, usually as a by-product of soap manufacture, from oils and fats, and can be made from animal fat or, in the case of vegetable glycerin, vegetable oil. Glycerin belongs to a special category of carbohydrates called polyols, which also includes sugar alcohols like sorbitol and erythritol. Like sugar alcohols, which I’ve talked about before, glycerin tastes sweet but it is not metabolized as sugar in the body and doesn’t cause a rise in blood sugar. For that reason, it’s sometimes used as a sweetener in foods marketed to diabetics and low-carb dieters.

Glycerin also has that moisture-attracting property. The same way that adding glycerin to a lotion helps keeps your skin stay plump and moist, adding glycerin to foods helps them stay moist. So glycerin is also widely used in food manufacturing as a preservative.

Is Glycerin Safe?
As with almost any substance, a small number of people have sensitivities or allergies to glycerin and it can be toxic if consumed in sufficient quantities. But as it’s typically used, to keep foods fresh or as a low-glycemic sweetener, glycerin is generally safe. It is not, however, calorie-free. In fact, glycerin contains slightly more calories than sugar—and it’s only about 60% as sweet, so you might need slightly more to get the equivalent sweetness. Also, as with sugar alcohols, consuming a lot of glycerin can produce a laxative effect, which may or may not be desired.

Here’s the bottom line on glycerin as an alternative sweetener: The main advantage is that glycerin does not affect your blood sugar. However, substituting glycerin for sugar will not reduce calories. And consuming it (or foods sweetened with it) in large quantities is not a recipe for good nutrition. I suggest that glycerin—like all forms of sugar and sugar substitutes—be consumed in moderation.

Main Uses
Glycerinis widely used in the food industry for two main reasons: it has a sweet taste, but has fewer calories than sugar; and it is hygroscopic, that is, it absorbs moisture from the air. It is therefore used both to sweeten foods and to keep them moist.  The compound is metabolized more slowly than sucrose, the type of sugar mostcommonly found in candy and in processed foods,  and therefore does not have such a dramatic effect on blood sugar levels. It also does not contribute to bacterial tooth decay. Foods marketed as being low in carbohydrates are often sweetened with glycerin.

Glycerol is a precursor for synthesis of triacylglycerols and of phospholipids in the liver and a dipose tissue. When the body uses stored fat as a source of energy, glycerol and fatty acids are released into the bloodstream. In some organisms, the glycerol component can be converted into glucose by the liver and, thus, provide energy for cellular metabolism.

Before glycerol can enter the pathway of glycolysis or gluconeogenesis (depending on physiological conditions), it must be converted to their intermediate glyceraldehyde3-phosphate in the following steps:

The enzyme glycerol kinase is present only in the liver. In a dipose tissue, glycerol 3-phosphate is obtained from dihydroxyacetonephosphate (DHAP) with the enzyme glycerol-3-phosphate dehydrogenase. Glycerol has very low toxicity when ingested; its LD50 oral dose for rats is 12600 mg/kg and 8700 mg/kg for mice.

The n=1 Test with Vaping 100% VG Juices
Just a very simple test regarding vaping VG juices and ketosis. I’ve seen a lot of discussion about the calorie content in the e-juices with propylene glycol and vegetable glycerin, but not any test to measure how it can affect ketosis. Let’s see my very quick experiment when vaping.





8:00 AM 3.1 mmol/L 77 mg/dL 16h Fasted, start vaping 1.0ml
8:15 AM 2.8 mmol/L 75 mg/dL added 1.0ml** 100%VG ejuice
8:30 AM 2.1 mmol/L 79 mg/dL added 1.0ml** 100%VG ejuice
8:45 AM 2.5 mmol/L 74 mg/dL added 1.0ml 100%VG ejuice
9:00 AM 2.3 mmol/L 77 mg/dL added 1.0ml 100%VG ejuice
9:15 AM 3.0 mmol/L 77 mg/dL stopped vaping
9:30 AM 2.5 mmol/L 81 mg/dL control
10:00 AM 2.6 mmol/L 78 mg/dL control
10:30 AM 2.2 mmol/L 77 mg/dL control

05:00 PM | 3.4 mmol/L | 73 mg/dL |  started vaping again

**Slight decrease in the production of ketones minutes after start vaporizing, but we can not blame the vaping or the meter directly, it would take more tests to confirm a real situation.

Assuming my case, vaping 5 ml twice daily (or even more sometimes), I would, per day, get calories worth of 10g Carbs. I still don’t know how much is absorbed and how much is exhaled, so let’s this. However, it costs energy for the body to process and break down bread, whereas inhalation of VG costs hardly any energy. I don’t know if it is insignificant. But, as I said before, it is not the question of how much energy PG and VG adds. What I am discussing is whether it can affect the metabolic process, slowing down the processing of fat. I am not sure of this at all. But it remains to be explained why vaping is not as effective as cigarette smoking when it comes to fat reduction.

Let’s say that small portions of carbs is ingested continually during the day and this continues day after day, year after year. Is this supposed to have no effect on the metabolic system? I’m still not so sure, so more n=1 tests are coming, next on PG.

Vaping, e-cigarettes and ketosis: how is it going?
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About Gabriel Machado

Gabriel Machado is engineer, blogger and fanatic for any health related subjects, specially on the realm of diet and nutrition. After having your life changed following a low-carb diet, became a keto-freak trying to spread the Ketogenic Lifestyle message to all over the world.

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  • Richard Snolly

    All e-cigs are created equal. There are hundreds of brands with simple products resembling conventional tobacco cigarettes to more high-end, sophisticated vape pens.