[samuelbrin]

I might have missed it, but doesn't look like ketone levels was one of the factors being measured. You can actually buy ketone pee strips at any drugstore for cheap. Would have been an interesting thing to track, since conventional wisdom says that ketosis is binary, you're in it or your not, and the actual ketone level doesn't affect the weight loss. I'm sure this has been put to the test in some experiments already, but maybe applying learning could teach us more and validate/invalidate this hypothesis

[aantix]

On a related note; NuSI (Gary Taubes's Nutrition Science Initiative for better nutritional testing) has not published their first results for the carbohydrate/insulin link to obesity, but Dr. Kevin Hall discusses the upcoming results in this video and some people may be surprised (including Gary).

_No Metabolic Advantage for Ketosis Found_

https://www.youtube.com/watch?v=MiUyjMjuLl0

[jtmarmon]

This situation has been highly debated among the keto science community. I call it a situation and not a study because they're publishing preliminary results for a pilot study. Hardly conclusive.

https://proteinpower.com/drmike/2016/05/06/contradictions-an...

[samuelbrin]

I wish I had data to back this up, but there is no chance I was in caloric deficit on the keto diet. I lost lots of weight at the time. Not claiming my body violated energy conservation, but clearly this is more complex than "you don't get weight loss for free so you have to exercise more". So many folks doing the keto diet are sucking down ungodly amounts of bacon, heavy cream, etc and losing weight

[ghshephard]

They are replacing even more ungodly amounts of calories in the form of carbohydrates with that bacon/cream. Honestly, you can only eat so much bacon before you get sick of it, and your body just screams "Yuck. Stop eating. I'm full".

That's not true of things like rice, noodles, bread, etc.. where for many people eat some, and your body is like, "Awesome. Bring it on" in a never ending cycle.

Put another way - Satiation happens a lot faster, and lasts longer, when you are eating protein/fats, than it does when you are eating refined carbohydrates.

I think that what made it clear to me, is that there are no metabolic chamber studies (where people's activity and diet are perfectly controlled) that have ever demonstrated significant variation from the calories in/calories out model. Carbs, Protein, Fats - doesn't seem to make a difference, your weight is simply a reflection of your metabolic output and caloric-intake.

Stephan Guyenet also has an interesting perspective here:

http://wholehealthsource.blogspot.sg/2011/08/carbohydrate-hy...

[samuelbrin]

I don't doubt for many that reduction in carbs amounts to reduction in calories. For others though, eating a lot, and not worrying about consequences, is a coping mechanism for how shitty the diet is. I'm super biased from my own past experience, but I was having 3000+ calorie days with minimal exercise and losing weight on keto. Open to the idea that I'm somehow wrong though :-)

[ghshephard]

They've tried all sorts of diets in metabolic chambers - and it's really quite amazing how closely the observed results track the predicted results. Determine a person's BMR, and then feed them a variety of diets higher, or lower, than that BMR, and watch their body mass (exc. water) increase, or decrease as expected.

Possibly the case that when you were eating carbs, you were putting away 3500 calories a day, and that dropped to 3000 calories a day when it was just meat? I know that just a casual stroll through the mall on a refeed day for me, I have zero difficulty putting away 6000+ calories - refined carbs are shockingly calorically dense.

Also - for some time on a Keto Diet, you are going to be dropping a ton of water - so the scale will be dropping like a rock, regardless of what your actual body weight is doing. Getting a DexaScan, or whatever lean/fat body mass assessment you prefer to see what's really going on.

[barney54]

The water loss is one thing I like about a low carb diet--you get positive feedback right away. It isn't real weight loss, but that doesn't matter. The point is to get started and feel like you have made progress in the right direction. Then the real, much slower, weight loss can begin.

[jtmarmon]

I don't contest that ketone level affects weightloss, but just to be clear, ketone pee strips don't tell you anything about your "ketone levels". They tell you the concentration of ketones expelled in your urine, which varies by a lot of things, like time of day and hydration levels.

Precision Xtra test strips will give you a far more precise and accurate measure of ketones in your blood and if you wanted to do anything quantitative like in this case study, you'd want to use those.

[samuelbrin]

Hmm I don't think you're right. I'm looking at an old bottle of ketostix brand, and it specifies Acetoacetic Acid, which seems to be some kind of ketone. Or maybe it's another byproduct?

Edit - Also, presumably the other factors like hydration and time of day could be tracked as well used to apply learning

[jtmarmon]

you're correct; had my terms jumbled. edited my comment for correctness.

[spearo77]

An interesting thing to note about the pee strips, is that your urine only contains significant ketone bodies if your body is not using them all up.

I use a glucose monitor with beta-hydroxy-butyrate (ketone body) test strips for accurate measurement.