Body's fat utilization per day?

[healthyvegan]

Jeff, I know in the published 10 day program results the median weight loss was 3.5lbs a week or a half a pound a day. Assuming this was all fat, that would be 1750~ calories a day metabolized and not replaced. I am trying to understand "fat balance" better and get some idea or direction of understanding what an average person fed only white sugar to energy balance every day for 10 days would expend in fat metabolism/fat balance? I know resting muscle can utlize fat, but also many environmental factors are at play here. I have this study showing excess carbs increased fat metabolism at a greater rate than replacement.

https://www.ncbi.nlm.nih.gov/pubmed/675 ... t=Abstract

To simplify I am looking to know how much fat a human under various conditions will use for their energy matrix for their specific anatomy. Anything out there to give me some ideas on our daily usage of fat absent dietary sources while in energy balance?

[JeffN]

Jeff, I know in the published 10 day program results the median weight loss was 3.5lbs a week or a half a pound a day. Assuming this was all fat, that would be 1750~ calories a day metabolized and not replaced. I am trying to understand "fat balance" better and get some idea or direction of understanding what an average person fed only white sugar to energy balance every day for 10 days would expend in fat metabolism/fat balance? I know resting muscle can utlize fat, but also many environmental factors are at play here. I have this study showing excess carbs increased fat metabolism at a greater rate than replacement.

https://www.ncbi.nlm.nih.gov/pubmed/675 ... t=Abstract

To simplify I am looking to know how much fat a human under various conditions will use for their energy matrix for their specific anatomy. Anything out there to give me some ideas on our daily usage of fat absent dietary sources while in energy balance?

So basically, a full course in metabolism in one post

The answer depends on so many variables that there is no simple answer. This is also why we see so many different answers as it depends on what variables they are controlling for, or not and of what time period.

The answer depends on whether the subject is fasting (zero calorie intake), dieting (negative energy balance), maintaining weight (energy balance equilibrium), or gaining weight (positive energy balance).

The answer also depends on whether we look at them for a few hours, a day, a week, or several weeks and months as the body adapts over time. When someone switches from a very high carb diet to a very low carb diet, the process will go through a few phases over the first few days.

However, for the average person in energy balance, they burn about 50% of their energy from fat and about 50% of the their energy from carbohydrate. As activity levels increase, the percent of carb goes up and the percent of fat does down.

This prior thread explains some of this

viewtopic.php?f=22&t=14103

Now, if I have completely misunderstood your question, let me know

In Health
Jeff

[healthyvegan]

However, for the average person in energy balance, they burn about 50% of their energy from fat and about 50% of the their energy from carbohydrate. As activity levels increase, the percent of carb goes up and the percent of fat does down.

THANK YOU! I know its a "calculus" of variables swirling around with metabolism. I am trying to simplify communicating how this diet works by talking about Fat Balance (saw Kevin Hall go over Fat Balance a bit in a NYU talk he did recently).

So the simplified version;

Mr McDougaller with 2000 cal TDEE loses weight by "fat shifting" from his plate to his waist by eating mostly carbs. Body is still doing the ~50/50 split & the carb conversion to fat has a ~30% energy cost so even though Mr McDougaller is eating enough he is expending more fat than being replaced while potentially being in equilibrium on overall calories?

It also seems that on a low protein diet the nitrogen pool would not be sufficient to convert the carbs into fat, too? The nitrogen heavy molecule of Acetyl-CoA is nitrogen dependent for the conversion of fat to carbs?



So on the McDougall diet if 50/50 is playing out in the 10 day program participants & that negative fat balance accounts for the dramatic weight loss, are any of the carbs being converted to fat in 10 program participants and then metabolized as fat? Is there a daily fat requirement beyond EFAs if energy equilibrium from carbs and protein exists? All the molecules are there in the soup.

Appreciate every moment of your time & answers. I know how everyone wants simple answers to complex multifaceted questions with infinite variables

[JeffN]

I just reread your original question and our discussion and realize, yes, I misunderstood the point of your original question.

So back to your original question ....

Jeff, I know in the published 10 day program results the median weight loss was 3.5lbs a week or a half a pound a day. Assuming this was all fat, that would be 1750~ calories a day metabolized and not replaced.

We can't make that assumption because we know it is not entirely accurate. And, the minute you start making assumptions (without actually validating them) you can't come up with a valid, let alone simple, answer. The answer will always be based on "IF......" and "IF" is not always true for everyone.

Weight loss and where it comes from can be influenced by many things including glycogen shifts, fluid shifts, fecal loss, hormones, disease state, genetics, exercise, exercise intensity, etc. In addition, starting body composition can greatly influence what percent fat each person would lose. Those with higher % body fat losing a higher percentage of their weight from fat. I discuss this in the following thread

viewtopic.php?f=22&t=8079&p=58408&#p58408


Remember, we have people who lose much more than 3.5, some who stay even and some who gain weight.

And fat cells are not 100% fat and that is why it is estimated at 3500 calories per lb and not the 4086 it would be if it was truly 100% fat, and another assumption is that all the fat is 9 cal/gm. I go over these issues and the related math in this thread, which I highly recommended reading, including all the links in it....

viewtopic.php?f=22&t=47836


Even our methods of measuring this are not always very accurate especially over short periods of time. This is why most of the results we hear about over the short-term in regard to this area have little value.

One way people try to measure this is through changes in body composition during the study.

However, when I worked at Pritikin, we had a state of the art DEXA that we used for Bone Density analysis and body composition analysis. I did an experiment to check the accuracy of it (as it is claimed to be the gold standard). I am very regular in my habits and consumed the same food everyday, at the same time, worked out the same, etc etc . The DEXA was calibrated and I measured my DEXA several times each day over a few days. My weight didn't change but the difference in body fat between these readings could be several percentage points (up and down) and I don't weigh that much or have much % body fat for there to be such a variance. These differences could have a huge impact on your experiment.

I found similar issues with hydrostatic weighing when involved with some research using it.

I am trying to understand "fat balance" better and get some idea or direction of understanding what an average person fed only white sugar to energy balance every day for 10 days would expend in fat metabolism/fat balance? I know resting muscle can utlize fat, but also many environmental factors are at play here.

There are so many individual variables that the only way to know this for sure would be to do this exact experiment and no one has that I know of. And, if you did it for the 50 people in the program, there would be differences and outliers (as we see with anything we measure) amongst them.

If you search PubMed you will find many studies trying to figure this out using all different variables. For a quick example

https://www.ncbi.nlm.nih.gov/pubmed/22735432

I have this study showing excess carbs increased fat metabolism at a greater rate than replacement.

https://www.ncbi.nlm.nih.gov/pubmed/675 ... t=Abstract

The problem with this study is very small sample size and it's based on one meal. The next meal could produce different results and actually be influenced by the composition of this previous meal.

To simplify I am looking to know how much fat a human under various conditions will use for their energy matrix for their specific anatomy. Anything out there to give me some ideas on our daily usage of fat absent dietary sources while in energy balance?

Unfortunately, there is no simple answer.

Probably the best method to do this is to measure respiratory quotient through indirect calorimetry or to use doubly labeled water (which is what was used in the recent exercise paradox studies).

https://www.ncbi.nlm.nih.gov/pubmed/21892558

My recommendation (IF I am understanding you correctly) is to start here with this recent review and go through the literature review and see what is known on the subject.

https://www.ncbi.nlm.nih.gov/pubmed/27818932

It's conclusion...

"An array of methodologies is available to measure various aspects of energy metabolism and none is perfect under all circumstances. The choice of methods should be specific to particular research questions with practicality and quality of data the priorities for consideration. A combination of complementary measurements may be preferable. There is an imperative need to develop new methodologies to improve the accuracy and precision of energy intake assessments."


In Health
Jeff

[healthyvegan]

Thanks so much Jeff. I am working on a video on "Fat Balance" for a new way to think about weight loss. Dr. Barnard just posted this new study https://www.eurekalert.org/pub_releases ... 061217.php showing on calorie controlled diets for the same amount of calories the plant based group lost twice as much. He seems to think clearing the fat out of the mitochondria made them more efficient and explains the added fat loss along with the fiber.

[JeffN]

I saw this when it came out. I would recommend taking a close look at the actual study before making any conclusions.

http://www.tandfonline.com/doi/full/10. ... 17.1302367

In Health
Jeff

[healthyvegan]

I'm still struggling to understand the over reach in conclusion in Dr Kahleova's study. They were both restricted -500 cals (so you'd expect over 12 weeks to have 12 pounds of weight loss with conventional thinking?)

The vegetarian diet was almost twice as effective in reducing body weight compared to the conventional hypo caloric diet (−6.2 kg [95% confidence interval (CI), −6.6 to −5.3] in V vs −3.2 kg [95% CI, −3.7 to −2.5] in C; Gxt p < 0.001)

So maybe the conventional group was just not that good at sticking to the diet or calculating their calories?

The marcos in each diet were not all that different...

The vegetarian diet (∼60% of energy from carbohydrates, 15% protein, and 25% fat) consisted of vegetables, grains, legumes, fruits, and nuts. Animal products were limited to a maximum of one portion of low-fat yogurt a day. The conventional diabetic diet contained 50% of energy from carbohydrates, 20% protein, less than 30% fat (≤7% saturated fat, less than 200 mg/d of cholesterol/day).

I just don't see how 5% different in fat could have such a dramatic effect in weight loss albeit animal fat vs veg. What am I missing?

[JeffN]

So maybe the conventional group was just not that good at sticking to the diet or calculating their calories?

I just don't see how 5% different in fat could have such a dramatic effect in weight loss albeit animal fat vs veg. What am I missing?

Well, first, I am glad you caught these 2 things, the issue of adherence and the issue that there was only a 5% difference between the 2 diets in fat, before making your video.

Second, the quotes you post above from the study are only describing how the diet and adherence were "defined" and "administered" (taught).

it does not describe in anyway how the adherence to the recommendations were tracked, measured, calculated, etc over the course of the study. This was not a metabolic ward study or a study where they were provided the (carefully measured) food, but a free-living study. That is always a problem as we know how inaccurate people are about following dietary recommendations. I have previously posted studies here that even when professionals were asked to track their diets they were up to 30% off. How much better are free-living people going to do?

There is also a phenomenon called the "regression to the mean" which means that over time, people shift back to what they were original doing before the intervention of the study. This has proven out in many dietary studies that over time, regardless of which diet they are put on, over the course of the time of the study, the all gradually shifted back to the SAD they were eating before.

So, without more info, you don't know and unless these calorie values, macronutrient values, adherence values were all carefully measured over the course of the study, this study ain't worth much at all.

You can write the author and hope they did carefully track all this and that they have all the info and for some reason just left it out of the study by accident, but I doubt that is true.

This is why tearing apart studies is SO important especially in light of the fact that the majority of stuff being published today will never be properly replicated and proven out.

In Health
Jeff