Fat Logic

[cosmicaug]

I'm pretty sure that rabbit starvation is a thing.

You shouldn't be pretty sure. Maybe it is a thing and maybe it isn't. The idea that it is a thing comes mostly from anecdotes.

I think you have this backwards. My understanding, which may of course be wrong, is that fat isn't converted to fat in the body. Carbohydrates are easier for the body to convert into energy than fats are - a gram of carbohydrates is more efficient a source of energy than fat is. But excess carbohydrates are stored in the body in the form of fat - consumed fats aren't stored as body fat.

Yes, your understanding is wrong. Fat is not converted to fat because it already is fat. You get a couple of lipolysis steps (one leading to free fatty acids and monoglycerides being released and another releasing a fatty acid from a monoglyceride) leading to the fats being absorbed as fatty acids in your small intestine. Fatty acids can be metabolized for energy or transported into fat cells*. There's absolutely nothing to prevent fatty acids from entering adipocytes (though they might first have to be released from lipoproteins). Once in the fat cell, re-esterification into a tryglyceride is uncomplicated. There's a hormone controlled, constant flow of fatty acids into and out of adipocytes. I repeat, there exists no magical barrier preventing fatty acids from being transported into fat cells and stored as triglycerides.

My understanding is that if you eat the same amount of excess calories in carbohydrates, you will gain more body fat than the same calories consumed in the form of fat.

This is what the Atkins diet promoters claim. They sometimes refer to it as a "metabolic advantage". It is an alleged magical inefficiency of the ketotic state that very low carbohydrate diets are supposed to be exploiting. This is why some people on Atkins type diets sometimes obsess over peeing on ketogenic test strips since some believe that the "magic" happens upon entering a ketogenic state. It is not supported by the evidence.



* Or other cell types but I digress.

 

[cosmicaug]

Regardless, burning more calories than you absorb is a necessary, but not always sufficient, pre-requisite to losing stored bodyfat. A previous poster linked a research review on bodyrecomposition.com . There are a lot of good articles on that site. Long and short of the argument: Both sides are right, and neither presents a complete picture.

Lyle McDonald basically wrote the book on ketogenic dieting*.



* Not that it there aren't others or that it's even the first one but it is good and very well researched.

 

[Roboramma]

If you can hold your breath, shouldn't you be able to override the biological drive to breathe?

Resisting the biological drive to breathe is entirely possible: it just requires training. Free-divers do it all the time. My own experience in the limited amount that I trained myself to hold my breath under water was that there's a point where the feeling of a need to for a breath goes from intense and seemingly undeniable to non-existent. At that point I just felt at peace and it was only the knowledge that I was going to pass out soon that would make me decide to breathe.

But one has to train to get to that point. I haven't worked on this in a long time and I think it would take me at least a week of consistent training to get back to that point. For others who haven't trained at all it would likely take longer.

Of course you don't control what happens after you pass out.

 

[theprestige]

Resisting the biological drive to breathe is entirely possible: it just requires training. Free-divers do it all the time. My own experience in the limited amount that I trained myself to hold my breath under water was that there's a point where the feeling of a need to for a breath goes from intense and seemingly undeniable to non-existent. At that point I just felt at peace and it was only the knowledge that I was going to pass out soon that would make me decide to breathe.

But one has to train to get to that point. I haven't worked on this in a long time and I think it would take me at least a week of consistent training to get back to that point. For others who haven't trained at all it would likely take longer.

Of course you don't control what happens after you pass out.

Simple, but not easy. Just like the methods and mechanisms of weight loss.

 

[marplots]

Simple, but not easy. Just like the methods and mechanisms of weight loss.

How does "not easy" even come into it? Being fat isn't easy either. I have noticed a great many "fat-strategies" employed by the obese to deal with both their food anxieties and the consequences of hauling around excessive mass. They have to deal with extra sweating and rashes, the logistics of minimizing stair use, a swath of clothing issues, and navigation problems of all sorts. And I haven't even mentioned the medical problems...

The choice isn't between easy and not easy, the choice is between training yourself how to be fat or learning how to be thin. Either is possible. The fact that someone has habituated to one skill set, and happy to accept the familiar chores, does not make that objectively easier than another skill set, as yet unattained.

 

[Prometheus]

How does "not easy" even come into it? Being fat isn't easy either. I have noticed a great many "fat-strategies" employed by the obese to deal with both their food anxieties and the consequences of hauling around excessive mass. They have to deal with extra sweating and rashes, the logistics of minimizing stair use, a swath of clothing issues, and navigation problems of all sorts. And I haven't even mentioned the medical problems...

The choice isn't between easy and not easy, the choice is between training yourself how to be fat or learning how to be thin. Either is possible. The fact that someone has habituated to one skill set, and happy to accept the familiar chores, does not make that objectively easier than another skill set, as yet unattained.

I would agree with this, and add that habituation is an often overlooked key to almost any attempt at significant life change.

 

[GlennB]

You shouldn't be pretty sure. Maybe it is a thing and maybe it isn't. The idea that it [rabbit starvation] is a thing comes mostly from anecdotes.

No, it's a biology thing. There's a limit to how much urea the human liver and kidneys can process and excrete in a day, and it falls far short of the amount that corresponds to a maintenance Kcal input from protein alone - theoretical Kcals that is.

 

[cosmicaug]

No, it's a biology thing. There's a limit to how much urea the human liver and kidneys can process and excrete in a day, and it falls far short of the amount that corresponds to a maintenance Kcal input from protein alone - theoretical Kcals that is.

That is a possible explanation an also what might be in dispute. In any case, despite the name, it would not really be a starvation issue as much as a metabolic dysfunction from accumulation of excess urea. More of a poisoning issue than a not being able to assimilate energy issue.

 

[Beerina]

BMI is a horrible index to use and is very inaccurate for determining a person's fat to lean body mass ratio. For example, BMI standards suggest that I'm morbidly obese at 5'2" and 215 lbs. I can accept that I'm overweight, but the BMI doesn't take into account my muscle and bone mass, which is significantly greater than most people.

However, doctors are well aware of lean body building types. BMI of standard sedentary obese people is reasonable.

More interesting was the link between healthy and unhealthy obesity relating to intra-abdominal fat. That too is well known w.r.t. diabetes and heart disease and hopefully is receiving major research attention.

Why don't they surgically remove someone's inside-the-abdomen fat ball and see what happens? Or look for why some deposite it there and others not. Stress seems to play a factor.

 

[cosmicaug]

BMI is a horrible index to use and is very inaccurate for determining a person's fat to lean body mass ratio. For example, BMI standards suggest that I'm morbidly obese at 5'2" and 215 lbs. I can accept that I'm overweight, but the BMI doesn't take into account my muscle and bone mass, which is significantly greater than most people.

It's good enough for a quick and dirty proxy to be used in population studies. That it may not roughly capture a given individual's body fat levels does not negate its usefulness for that application. If anything, it may systematically underestimate overfatness (I did not get that link from this thread, did I?).

 

[rustypouch]

It's good enough for a quick and dirty proxy to be used in population studies. That it may not roughly capture a given individual's body fat levels does not negate its usefulness for that application. If anything, it may systematically underestimate overfatness (I did not get that link from this thread, did I?).

I think I put that in the thread earlier. But is worth repeating.

 

[Upchurch]

FWIW

Why It Was Easier to Be Skinny in the 1980s

They found a very surprising correlation: A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher. In other words, people today are about 10 percent heavier than people were in the 1980s, even if they follow the exact same diet and exercise plans.

The actual study the above article is referring to

Conclusions

Factors other than diet and physical activity may be contributing to the increase in BMI over time. Further research is necessary to identify these factors and to determine the mechanisms through which they affect body weight.

 

[marplots]

FWIW

Why It Was Easier to Be Skinny in the 1980s

The actual study the above article is referring to

I wonder if "lazy" was one of the variables?

 

[GlennB]

I wonder if "lazy" was one of the variables?

Possibly. If the 'exercise' calculations are limited to formal exercise plans then overall lifestyle might be a consideration. Walking/cycling to school vs. bus/car and the like.

 

[marplots]

Possibly. If the 'exercise' calculations are limited to formal exercise plans then overall lifestyle might be a consideration. Walking/cycling to school vs. bus/car and the like.

If calories in vs. calories out is valid, then it would have to be something like that. On the other hand, if it's the magic of bad calories vs good, then the calorie source would be a better explanation.

 

[Upchurch]

If calories in vs. calories out is valid, then it would have to be something like that.

Granted, only the abstract is available, but I think you missed the first line of the conclusion:

Factors other than diet and physical activity may be contributing to the increase in BMI over time.

It may not "have to be something like that." It may be that something else is at play.

 

[marplots]

Granted, only the abstract is available, but I think you missed the first line of the conclusion:

​

It may not "have to be something like that." It may be that something else is at play.

True enough. There's always the possibility of a "something else."

 

[rustypouch]

True enough. There's always the possibility of a "something else."

Would that "something else" be bad data? From the abstract, it says that the data about food intake was from surveys, so I'm assuming this means it was self reported. People in general are terrible at recalling and reporting what they eat.

An older study: http://www.nejm.org/doi/full/10.1056/NEJM199212313272701

underreported their actual food intake by an average (±SD) of 47±16 percent and overreported their physical activity by 51±75 percent. Although the subjects in group 1 had no distinct psychopathologic characteristics, they perceived a genetic cause for their obesity, used thyroid medication at a high frequency, and described their eating behavior as relatively normal

Here's a good discussion about self reporting (a bit long, and unfortunately I couldn't find a succinct quote): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3025654/

And there are several papers about faulty self reporting, and how it can negatively affect research and dietary recommendations. For example:

http://www.nutraingredients.com/Research/Self-reported-food-intake-may-compromise-research-findings
http://www.andjrnl.org/article/S2212-2672(14)01048-X/abstract
http://www.scienceworldreport.com/a...ing-diet-impact-nutrition-recommendations.htm
http://www.researchgate.net/publication/7166671_Ingestive_Behavior_and_Neurosciences

For a more info-tainment look at this, there's the British show "Secret Eaters." They take people who claim to eat well, but can't seem to lose weight, and following them for a week. They're normally shocked at how much they eat, compared to how much they think they do. It's on YouTube. Here's the first episode:



Coming from a critical thinking perspective, I do think that it's reasonable to accept that people are eating more, knowingly or not, especially with the proliferation of foods designed to keep people eating, and the increasing amount of liquid calories. (side rant: people who want to lose weight, but are unwilling to give up their daily 4-500 calorie 'coffee' bother me.)

I find it much harder to accept that an undefined "something else" has had such a drastic effect over the last twenty-five years, and only in certain industrialized countries.

 

[marplots]

(Very good post snipped for brevity)

I find it much harder to accept that an undefined "something else" has had such a drastic effect over the last twenty-five years, and only in certain industrialized countries.

One tries to keep an open mind. Of course I would expect known mechanisms and relationships to give the better answer, but new information is welcome too. Happy to be surprised.

 

[Upchurch]

Would that "something else" be bad data? From the abstract, it says that the data about food intake was from surveys, so I'm assuming this means it was self reported.

Wrong kind of survey.

The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews and physical examinations. The NHANES interview includes demographic, socioeconomic, dietary, and health-related questions. The examination component consists of medical, dental, and physiological measurements, as well as laboratory tests administered by medical personnel.

ETA: One would think a methodological problem like that, if there was one, would be caught in peer review.

I find it much harder to accept that an undefined "something else" has had such a drastic effect over the last twenty-five years, and only in certain industrialized countries.

Maybe, maybe not. This is only one study. However, from a critical thinking perspective, it cannot be disregarded simply because it does not fit with what you already believe to the case.

The theory must fit the data, not the other way around.