Yes, if you want to see how each diet really works, test it on people who actually do it correctly.

Calculating the amount of weight lost by ketones leaving the body when a person is in deep ketosis was based on the weight of ketones detected in the urine in milligrams per deciliter of urine. Assuming that a person pees one liter per day, the weight of all lost ketones in a year was found to be slightly over one pound.

This sound to be very small, but if you know how many pounds of fat can produce a pound of ketones, you may change your mind about that. I can't remember numbers, but I know that a pound of ketones come from the consumption of a large amount of fat tissue.

Concerning diarrhea, I know that whenever I have one, some of the sunflower seeds which I eat with my salad find their way to the toilet in a mysterious way!

I have just checked this subject on the internet and I came up with a web page which starts with:

"During a diarrheal episode, the body cannot absorb nutrients as well as it can when it is healthy. Nutrient intake may fall as much as 33% during the first days of a diarrheal episode."

While that is true in theory, this would artificially inflate the performance of diets that are actually quite difficult. Yes, it should be known, but those who serve the public health, including health care providers, need to know what works in terms of what *they* can do. Which is not to conform to a diet but only, generally, to advise.

What *advice* is most effective?

It is inordinately difficult to measure compliance to diets. Where it is really necessary for a study, the study subjects are typically sequestered. They comply because that is all the food they are given! This is quite expensive.

It is theoretically possible now to monitor compliance without this, there are now digital solutions that would enable monitoring of compliance, but it would still be difficult.

And, as I'm pointing out, it is not really the question that needs most urgently to be answered. Doctors don't really need to know what is the ideal diet, they need to know what is the ideal advice. And that is much easier to test. And this study tested it.

With good research, I'd think that reasonably hypotheses could be developed as to an ideal diet, which is probably a whole range of diets depending on individual characteristics. Then these hypotheses could be tested under more controlled circumstances, and some kind of knowledge developed about "ideal diet" -- really ideal "diets."

But it would still remain true that the best diet to recommend might not be the "ideal diet." And it really begs the question. Is an ideal diet one which maximizes survival in years, or health by some measure (these two are not necessarily the same), or some kind of integrated satisfaction. Is thirty years of misery better than twenty years of enjoyment?

There are quite a few people out there who are saying, don't worry so much about restrictive diets, just make sure you enjoy your food. It's not bad advice!

Had I followed it, I'd have been eating much more fat and probably substantially less carbs than I ate because of the bad medical advice that became so common.... butter was my favorite food, and meat.

Potatoes, yes, but about as much butter and sour cream as potato....

Was my instinct (or the product of my early childhood, maybe) better for me, or the shallow medical advice? I don't know.

But I now eat much more like how I always wanted to eat. A bit less carbs, to be sure, and definitely much less sugar, but my enjoyment is just as high now as it ever was. Butter can make up for a lot! And cream in my coffee and so many other amenities that make for fabulous food (including fresh vegetables, salads, and more attention to preparation). As to my sweet tooth, well, the concession I make to modern science is sucralose, which I like as much or better than sugar.

I wrote a great deal about this (maybe a year back?). Here is the central problem. Yeah, there is the law of conservation of energy, and the law of conservation of matter. There is no law of conservation of calories, by the way, but the laws of energy and matter lead to some kind of calorie conservation law. Calories in food are a measure of the potential energy of burning the food. That potential energy cannot just disappear. But it can go into a number of different places.

I'll get to the real problem in a moment, something that totally escaped me when I first wrote about this issue, and which has apparently escaped the attention of far too many who should know better. But to finish the first thought:

The caloric potential energy of the food we eat can go to:
(1) heat.
(2) work.
The "calories burned" would be the sum of these two, but a given caloric content of food does not necessarily produce the same heat or work when burned by different metabolisms. In particular, to accomplish a given amount of work, more or less waste heat may be generated. The body is capable of adjusting for this by increasing the disposal of heat through perspiration and other methods. So it is possible that one kind of food, "so many calories" actually produces more or less heat than another kind, or even the same kind under different circumstances.
(3) excreted calories.
(4) stored energy, typically as body fat.

Excretion is often neglected. To some extent, this is justifiable, it appears that the body is ordinarily quite efficient at squeezing the caloric content out of food and either burning it or storing it, but, this will bring us to our second and major point.

Food "calories" are not "thermodynamic calories." There is a multiplication factor used to convert thermo calories, the kind subject to conservation laws, into food calories. I think it is called the Atwater factors, having been developed by Atwater circa 1900. Atwater factors compensate, in theory, for utilization efficiency differences between foods, taking into account, for example, that fiber carbs are typically not burned, but are only excreted.

And publication of calorie figures for foods are based on a one-size-fits-all collection of Atwater factors.

Thus we have the possibility that true caloric utilization of food differs from what you would expect from using food calories.

Just for starters, moving calories around from one substance in the body to another, from carbs to glucose, from protein and fat to ketones, takes energy, energy that is dissipated as heat and not as work. It can get very complicated.

The idea that there is some kind of law of "conservation of calories," thus, is based on a couple of misconceptions, as it is usually stated.

I've seen writers claim that those who reject "conservation of calories" are rejecting the laws of physics. If it were real thermodynamic calories we were discussing, that would be true, though there would still be the matter of the complex relationships between work/heat/excretion.

But it is *not* food calories that you see on food labels and in statements about recommended caloric intake and the like. It is adjusted calories, adjusted based on a very old set of assumptions and primitive measurements, not necessarily true for all dietary contexts and people.

Thanks ABD. I agree with all you've written. We use (burn) energy in various ways, including excretion. We also burn energy in the ways of "inefficiencies" as has been described above. There is a lot of information to support this.

But what about claims that solely due to the ratio of protein, carbohydrate, and fat that we consume, we somehow put ourselves into calorie deficit that can never be overcome?

I am in ketosis this very moment, and will be whether I stay on my eating plan today or whether I eat a steak, 4 oz of cheese, 6 pieces of bacon, 2 cups of romaine, and half a chicken for dinner. In that latter example, I will exceed my caloric requirement for the day -- and remain in ketosis -- and still get fat. Yes?

In the absence of insulin, it is very difficult to put on weight, fat in particular. If you eat near zero carb and keep your protein intake 'reasonable' i.e. around the mark of your normal daily requirements, you can over-eat fat to an alarming extent and not gain weight. Friends have done this for varying amounts of time including a physiology student who was in the neighborhood of 185 lbs that was eating around 10K Calories a day on a ketogenic diet for about 6 weeks and didn't gain a pound. Most days to get his calories up he would be eating sticks of butter and/or drinking glasses of olive oil.

Also, in the 'healthy' body, there does seem to be something to the set-point idea about body weight. One mechanism the body uses to keep an established weight is regulating how much heat you throw off. I'm sure most people can think of times when they are dieting they feel cold, conversely when 'over-eating' they will feel very warm. It's a known phenomenon, look it up. Anyway, the point being is that the body isn't a bomb calorimeter and regulates it's metabolism depending on quality and quantity of food it takes in.

Kind regards

What claims? I've never actually seen any claims that one can put themselves into a "calorie deficit that can never be overcome". I think this is a straw man.

Nope....if your weight in your profile is correct (355-pounds) then the above, even with the chicken being 2-pounds of meat (USDA Nutrient Databased "Chicken, roasting, meat only, cooked, roasted.....2 pounds) is only 1549-calories for the day (if your steak is 4-ounces too)....if the steak is 8-ounces you're still only up to 1778-calories.

Too many for you to lose weight?

Hardly!

It's probably too few for sustained long-term continued weight loss; add to this you "may" have difficulty eating that much protein though (165g-199g) in a day since you really only need about 130g. But with ketosis and gluconeogenesis, you could use 165g in a day (with 4-ounces steak) or .....but an 8-ounce steak might just be too much protein with 199g....either way, if you could eat that much protein, you'd still would be in a huge calorie deficit.

Well I can eat a heck of a lot of anything...protein or not!

So when Dr. Atkins says that calories...even on 10g carbs a day...matter, what is he saying? What does that mean for calorie counting?

It is not intended to be a straw man...I am not seeking to debunk, only to understand. There are claims that by eating fat and protein, and little carbs, that one can eat as many calories as they want and not gain an ounce. Just above, a poster claims no weight gain on a 10K calorie a day intake. What is one to make of such claims?

Dr Atkins said in his books that calories count. What does this mean?

It is possible to eat low carb and over eat to the point of not losing any weight. Because the mechanism the body uses to store fat requires insulin, it is difficult, if not impossible for most to gain body fat on strict low carb.

Dr. Atkins did indeed say calories count, but one a low-carb diet (whether it's Atkins, protein power, naeanderthin - basically any of the diet options where carbohydrate is 60g or less per day) one often and usually does not have to count calories like with other calorie restricted diets such as low-fat.

That's one of the beauties of low-carb - you don't necessarily have to count calories (some people do at some point, most definitely, but many never have to) because of the powerful effect adequate protein and fat has on satiety sensors in our metabolism.

For example, both fat and protein trigger CCK in the stomach - it signals the brain you've eaten, have nutrients to process and calories to work with. Carbohydrate does not trigger CCK or any other gut hormones to communicate with the brain you've eaten and tell you to stop.

Another critically important hormone is PYY - it too signals the brain you've eaten and is triggered by both protein and fat. It is only minimally triggered by carbohydrate and that's when protein and/or fat is also in the mix of food consumed or beverage drank....the driving trigger is protein and/or fat for this hormone.

Then there is insulin - insulin is secreted by consumption of both protein or carbohydrate, but not fat. Carbohydrate causes a higher rise in insulin, but protein does stimulate insulin because amino acids also need insulin to do their work. The rise just isn't usually as high (but does vary by source of protein), and as amino acids are shuttled around, the decline in insulin doesn't go as low following consumption of protein and thus hunger is triggered again in the same way.

Amino acids can also be shuttled over to the glucose pathway for energy and protein can be converted to glucose --- thus the body is allowed to control availability of glucose, and the need for insulin more tightly than when assulted with insanely high amounts of carbohydrate as is typical in the SAD (standard American diet).

Basically, protein & fat allowed ad libitum, with carbohydrate restricted, offers you a lot more spontaneous - don't think too hard about it - control of your calorie intake without having to count your calories.

Your own example was really great --- you would have thought it an insane intake of calories, because it sounds like so much food with so much fat, fat, fat......but even if that steak was 8-ounces and the chicken was 2-pounds of meat.....you wouldn't have even broke 1,800-calories in the day.

As I say to those who ask.....a low-carb diet allows you to find your satiety because it allows you to eat liberally of the very basic essentials we require (protein, fat and nutrients) and tells us to shun the stuff we do not have an obligate requirement for (carbohydrate) to survive.

Think about that one for a moment - you get to "find your satiety" again....after years of being told to reduce your fat and calories.....you get to find that level for yourself just be eating as you wish of protein and fat with a fairly good selection of non-starchy vegetables the first few weeks (before you add more carbs back). That's pretty darn empowering for a person - and scary too.....because with other dietary approaches it is easy to overeat and overdo calories.....with controlled carb/low-carb, while still possible, it's just harder to do that.

Many will find as they lose weight they need to count calories, but like I said, most don't have to when they are getting started if they just follow the rules as they're written and let the diet work it's magic on the metabolism.....oh wait, it works because it's not magic, it is metabolism! <grin>

I have my own opinion on this. He told us to not allow ourselves to get hungry. Eat when you feel like you need food. I think when he said this he wasn't allowing for the fact that there are some people who eat for reasons other than hunger. So he later moderated his advice to try to keep us from going overboard. He was trying to tell us we didn't have to be hungry, but that it wasn't a license to eat all the time.

I can certainly eat as much as I want and not gain any weight - as long as I avoid carbs and too much alcohol.

"As much as I want" does not mean "unlimited". How much I eat IS limited - by how much I want. Since my insulin is under control, how much I want happens to be approximately the number of calories needed to maintain my weight, which is somewhere between 1200 and 1800 (guestimated). Of course, this is after a couple of years of low-carbing. When I first started, for the first couple of months I lost several pounds a week on probably twice as many calories as I eat now, but at a somewhat higher fat/protein ratio.

Thanks to everyone for the information. I have some reading to do. Any scientific sources would also be helpful. I know it takes a lot of time to write all of this out, so your replies are appreciated.

I have 9 graduate hours of nutrition studies from...well...a while back, so just enough to be dangerous. We actually did study ketogenic diets and the information, as I recall, was not derogatory. Yet the "metabolic advantage" is not clear to me...scientifically. Yes there are the one or two Fineman studies, but they only point to possible mechanisms...and I know absolute proof of excreted energy may be impossible.

I have some research to do. Thanks for the leads. One thing for sure, I don't have to understand to know it is working and working well for me for the past 61 days.