Keto for the Win – Again

Here is another cross-over study showing the advantage of the keto diet over a medium carbohydrate diet (Johnstone AM, Horgan GW, Murison SD, Bremner DM, Lobley GE. Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum. Am J Clin Nutr. 2008 Jan;87(1):44-55.).

Ad libitum energy intakes were lower with the LC diet than with the MC diet [P=0.02; SE of the difference (SED): 0.27] at 7.25 and 7.95 MJ/d, respectively. Over the 4-wk period, hunger was significantly lower (P=0.014; SED: 1.76) and weight loss was significantly greater (P=0.006; SED: 0.62) with the LC diet (6.34 kg) than with the MC diet (4.35 kg). The LC diet induced ketosis with mean 3-hydroxybutyrate concentrations of 1.52 mmol/L in plasma (P=0.036 from baseline; SED: 0.62) and 2.99 mmol/L in urine (P<0.001 from baseline; SED: 0.36).

These men were allowed to eat as much as they wanted but chose to eat less when they were given Low Carb food.

 

Am I Keto or Low Carb?

Someone in a Fakebook group posted that keto is:

eating in such a way that about 80% of your calories in come from healthy fats, about 15% from protein and 5% or less from carbs

My median actual maintenance macros for the past 3 months (Maintenance Macros – 2018-07-20) were:

  • Protein: 181g
  • Carbs: 28.52g
  • Fat: 159.6

In terms of percent of calories by macronutrient, that is:

Macro g kcal/g kcal Percent
P 181 4 724 31.8%
C 28.5 4 114 5.0%
F 159.6 9 1436.4 63.2%
2274.4

So I am not keto by this gentleman’s definition since my protein is twice his listed amount and my fat is much lower. My protein number is twice his and my fat number is lower than his.

However, my blood ketone meter shows that I am in ketosis. Here’s the number from yesterday:

And that is nutritional ketosis with a “high” protein intake.

 

Blood Sugar and Fasting

A while back, I noticed that my Blood Sugar peaks around the second day of extended fasting. George Cahill did the seminal work measuring blood markers during starvation (Cahill, George. Fuel Metabolism in Starvation.). Here’s an interesting chart from that study that explains the sources of glucose during starvation.

This demonstrates the increase in blood sugar around day 2-3. Diabetics are particularly adept at GNG. Eventually though, even that reduces as the body becomes physiologically Insulin Resistant.

The chart can provide some idea of what happens in a ketogenic diet. Although someone on a ketogenic diet is eating enough food, their exogenous glucose is greatly reduced due to the low carbohydrate content of the diet. Glycogen stores lower next. When the glycogen stores get low the body then upregulates Glyconeogenesis (GNG).

This could also explain why when I see an increase in blood sugars on one morning I often see a drop in weight the following morning. The body is signalling that it is switching fuel to up-regulated GNG due to dropped Glycogen stores. Although these two sources are of the same magnitude in Cahill’s chart above they could well be less equally matched in a diabetic. It is possible that GNG in a diabetic outpaces the ability to pull from Glycogen stores.

 

Breath Ketones – Ketonix

There is a correlation between level of acetone measured in the breath and fat loss. More from the study (Joseph C. Anderson. Measuring breath acetone for monitoring fat loss: Review.  Obesity (Silver Spring). 2015 Dec; 23(12): 2327–2334.) notes in one study that:

1 lb/week of fat loss corresponded to BrAce = 67 nM (1.7 ppm). Every ∼40% increase in BrAce (e.g., from 67 to 94 nM) corresponded to an additional ∼0.5 lb of weekly fat loss.

Another study noted that:

Fat loss and BrAce were greater for experimental subjects than controls.

Maintaining a BrAce= 85 nM (∼2.1 ppm) corresponded to a fat loss of 227 g/week (0.5 lbs/week).

Relating to the Low Carb

Adults in nutritional ketosis have BOHB ranging from 0.5‐3.0 mM, which corresponds to a breath acetone range of 4 to 30 ppm.

 

Day 3 of New Maintenance Numbers

I am a mission to maintain my weight and stay Low Carb.

Here’s my macros from yesterday:

I tweeked my macros for a goal weight of 165-175 to:

  • Protein: 165-175g
  • Carbs: 20g
  • Fat: 145-155g

So, yesterday I hit my range. How’s my weight doing?

So far my maintenance numbers are not stabilizing my weight. Today I did a long bike ride and my legs are on fire. That could add some water weight tomorrow. Burned 800+ calories in the three hour 20 mile ride.

My food yesterday was:

My ketones on the Ketonix are:

10.2 PPM is about 1mM:

Blood sugar

  • 77 after bike ride
  • 87 when I got up this AM

So all signs are good.

 

Day 1 of New Maintenance Numbers

Earlier I found my maintenance macros.

I ate to the macros today and did OK I think.

My targets are listed there (minimum targets). I didn’t get in quite enough protein and I got in a bit more fat. I did CrossFit earlier today and enough yard work that my watch detected it but I didn’t include that explicitly (it’s there in calories net). My goals were:

Ketonix?

I am back to feeling like I am in ketosis (taste in mouth) so I broke out my ketonix and I got this:

7.6 PPM corresponds to somewhere around 1 mM on the conversion chart.

That’s in nutritional ketosis range. So far, so good.

I don’t feel full or hungry. Here’s my food log for the day:

Not bad food choices.

 

Is this Keto?

A very common question for those of us who eat a keto diet is “Is this [whatever] keto?”. Along with it comes comments like “you mean you can’t eat bread [or whatever]”.

You can google almost any food with the phrase Nutrition Facts to get the carb values. For instance “google banana nutrition facts” returns:

The total carbohydrates for a medium banana is 27g. I subtract off fiber because your body doesn’t digest fiber (although the microbiom in you does) so the next carbs is 23.9g. That’s more than a day’s worth of carbs in one medium banana. So no, bananas don’t fit in keto numbers.

It’s down to carbs

In the end, it’s as simple as the number of grams of carbohydrates. There are no hard and fast definitions of what constitutes Low Carb and what constitutes ketogenic. The technical answer is what amount of carbohydrates you can eat in a day/meal that keep you in ketosis.

What is Ketosis?

But that begs the question of what constitutes being in ketosis. There’s also no accepted range of numbers or measurement methods. But the idea is that your body is using ketones for fuel. Even that is not an absolute since everyone uses some mixture of ketones and glucose. If you do an extended fast your body will generate glucose from your liver which converts fat to glucose in a process called Gluconeogenesis (GNG).

The easiest thing to measure and track are carbohydrates using a scale and an app like Cronometer which can show you the total number of carbs in your day.

Measuring Ketones

Ketones can be tested by three methods; blood, urine and breath. Each of these tests measure chemicals produced as a byproduct of ketosis. There’s some correlation between these three measurements but even that is not absolute.

Nutritional Ketosis Measures Blood Ketones

A widely accepted method is to use blood ketones and measure them against a standard. Except that there is no standard. Often cited is Stephen Phinney’s definition of “nutritional ketosis” illustrated below:

 

This says that blood ketones in the range of 0.5 to 3.0 mmol are optimal for brain and muscles.

Is this Food Keto?

Using this definition any food which you eat over a meal/day that drops your blood ketones below 0.5 mmol is not keto. But there’s no easy mapping of how many carbohydrates it takes to push someone to below that number. A commonly asserted amount is 20 grams of carbohydrates per day will take a person out of nutritional ketosis. For most people this number will be adequate. For others it may be too high and for others it may be too low.

The Only Way to Know is to Measure

The only way to know for sure is to measure the effect of a particular food or activity on your ketone levels. And testing isn’t cheap at around $5 a test strip. I’ve used the Precision Xtra meter for my measurements but I never actually mapped carb amounts to ketone levels. I mostly tracked the ketone levels vs days of fasting.

Cheaper Way to Measure

A cheaper way to measure is urine test strips. They are around $5 for 50 strips. You pee on a strip and compare the color of the strip to a scale. They work well for most people (at least at the beginning) but are affected by urine concentrations (which is a function of your level of hydration). They are also slow to react to diet changes. They can indicate what your level of ketosis was hours ago.

Another Expensive Way to Measure

I also bought a breath ketone measurement device, the ketonix. It is fairly expensive but can be reused.

The trouble is there’s a messy mapping from breath to blood ketones. Here’s the scatter diagram from breath to blood ketones with the best fit curce. Going up from 0.5 mMol to the line shows that that’s something like 2.0 PPM.

 

The ketonix has a USB interface and the data can be downloaded to your computer. Here’s a screen shot of one capture showing the level at 5.4 ppm which would be around 1 mMol.

Conclusion

In the end, the best way to be in ketosis is to eat a very limited amount of carbohydrates such as less than 20 grams a day.

 

Ketonix Converter

Here was my original review of the Ketonix unit (Ketonix Notes). The review was largely negative based on the performance of the unit. Ketonix came out with new software which has useful improvements.

The new Ketonix software has a zoom mode. Here’s screenshot:

I just blew 5.4 ppm. But what does that correlate to on a Blood Ketone scale?

Looks like that is somewhere around 1 mM which is in the optimal nutritional ketosis range of Phinney:

Interpreting the numbers

From the User Manual.

Another view of the same results taken from this study (Obesity (Silver Spring). 2015 Dec; 23(12): 2327–2334. Measuring breath acetone for monitoring fat loss: Review.  Joseph C. Anderson):

Ketonix Notes

Update 2018-05-09: Ketonix has updated their software and it gives better results. This post (Ketonix Converter) shows how to interpret the results. I feel better about my purchase now and am glad I didn’t return the unit.

The Ketonix 2017 model that I recently purchased has been disappointing. Previous year models seemed to work better for others.

Seems that the reason they were better was that the previous models used a different unit of measure and produced a wider range of “normal” Ketogenic readings.

The new scale is in PPM which is a lower scale than the previous model used. From the article: Measuring breath acetone for monitoring fat loss: Review

In normal healthy individuals, BrAce can range from 0.5 to 2.0 ppm. Adults on ketogenic diets (e.g., high fat with low carbohydrate) can have elevated levels of up to ∼40 ppm.

The article includes a graph which has the same data:

This actually correlates to what I measured with my Ketonix. I got numbers from 4 (in Ketosis) to 22 (when fasted 10 days).

That correlates to the scale above which shows a Ketogenic Diet in an adult to go from 2 to about 40.

The problem is that the middle of this Ketogenic Diet scale is 10. It took me several days of fasting to get to this level. So for normal Ketogenic dieting there’s not enough scale to blink the colored LEDs on the unit. If you look at the fasting scale you can see I never reached the higher levels I should have been seeing at 10 days into a fast.

Seems like the unit sort of works and sort of doesn’t work. If it is accurate for PPM then I would never see a number above 50% if I was at the very top of the Ketogenic diet scale – which is not realistic.