sorry for being obtuse, can someone expalin how the doubly labelled water measures calorie intake?

the link explains how it can be used a a proxy measure for energy expenditure, but I can't make the leap to measure energy consumed from that explanation.

(p.s. I was a biochemist/cell biologist, so you can throw around scientific terminology but don't assume I know any "bigger than an organ" biology)

This is a good read to answer your question.

Validation of the Doubly Labeled Water Method
http://www.jstor.org/pss/30158022

Patrick

EDIT: This one is even better: http://www.ajcn.org/cgi/reprint/86/4/1251.pdf

EDIT2: Best one so far. http://jn.nutrition.org/cgi/content/full/129/10/1765

Interesting!

In a nutshell, they use the change in body fat mass and the real energy expenditure (using DLW) to discover what the energy intake was.

Patrick

Late to the table..sorry.

I'm a big fan of GCBC. And...the only point that the Weitology corporation (which is what's speaking really) is trying to make is regarding calories. It seems from what I've read of "real" people here on the forum...calories do count...especially in mid life...enough said. He can win that one.

However, the most important revelation I got from reading GCBC it is about the value of fat metabolism over carbohydrate metabolism for your whole body. EVERYTHING feels better for me on low carb as opposed to low fat.

Plus the bonus of not having to constantly fight cravings to keep those calories in check. What a gift!

To me.... if it's easier...it must be what's right for my body.

I say read a lot and keep sharing what you learn here. We all have to figure it out for ourselves and I'm still on the quest!

bw

This makes me think of Doctor Davis, or Doctor Bernstein. Taking the most precise measurements of an individuals metabolism that you can, change one thing at a time. If there's an improvement, continue, if not, try something else. With time, you may come up with something that will help many individuals.

Working from the masses backwards (epidemiology) will always lack the resolution needed to get a clear picture. And any mistakes you make make will cause damage to a lot more people.

Maybe 'energy homeostasis' is part of the answer. The amount of fat on your body determines the amount of hormone (leptin?) sent to the brain. From this, the brain creates a 'setpoint'. This setpoint is used to regulate appetite. And the brain thinks that if fatmass is stable, everything is oké. Now if you start losing weight (fat), the brain thinks you are starving and will do everything it can to make you eat more to restore equilibrium.

I think this explains the jojo effect. The good news is that you can 'reset' the setpoint. From what I understand it takes about 6 months on your desired weight level before the brain conceives this as the normal state. Now the brain will do everything it can to keep you at this new weight.

Let's face it; appetite and hunger are very powerful signals. Having the brain to support you will help! But allow your system to accept the new status quo. In other words : losing the weight is only half the problem; staying at that weight for at least 6 months is the other half.

Just google for 'energy homeostasis' if you want to learn more.

Do you mean that I should stay hungry during the time my brain figures out it's the new weight? That won't work. Do you know about the Minnesota semi-starvation experiment? They stayed hungry for a long time. The result? Emaciation and neurosis. http://en.wikipedia.org/wiki/Minnes...tion_Experiment

Your explanation implies that the brain (i.e. our behavior) has the ability to control homeostasis. It does not. The reality is that our behavior is controlled by our body's fuel requirements and status. When we are more active, hunger increases to compensate. When we are sedentary, hunger decreases to compensate. When we eat more, activity level increases to compensate. When we eat less, activity level decreases to compensate. Indeed, when we intentionally reduce our total caloric intake, hunger will increase proportionately and increasingly, i.e. it will gradually occupy all of our thoughts and time until we ultimately go crazy. We would go just as crazy if we were to eat more food but were prevented from moving or going outside.

There's the possibility that homeostasis can be made to change but it would be very difficult to do so if the dietary pressures, i.e. the carb intake, remained the same. Indeed, it would be just as difficult to remain at the same weight if we cut out all carbs.

Starvation may physically not be the same as the situation that you are not physically starving, but your brain 'thinks' you are. The experiment in Minessota was about actual starvation.

And yes, I do think the brain works with setpoints. And if the actual weight deviates from the setpoint, the brain both interferes with your energy intake and your energy expenditure. But it may not work on a daily basis. But over time it may.

But I am not an expert on these matters, so I could very well be wrong. But you stimulate me to do some further reading because I find this an interesting issue.

Regards,

André

There's a world of difference between starvation and semi-starvation. The Minnesota experiment looked at semi-starvation. The experiments that looked at starvation use the word fasting as in "studies in prolonged fasting". For example, in semi-starvation hunger is omnipresent while in fasting hunger disappears after a short time. This tells us that there's more fuel available in fasting than in semi-starvation. It's a contradiction but that's the logic and once we look at it more closely we understand why that is so.

The brain is not the leader in the equation, it's the slave. The brain obeys the fuel requirements of the body. It does so by increasing or decreasing hunger which will force us to eat more or less. It does so by increasing or decreasing activity level which will force us to move more or less or to apply more or less effort to our movements. Think of the body as the means by which our cells acquire fuel. In other words, when our cells require fuel, they tell our brain to go get it and the brain obeys by changing our behavior, i.e. we hunt/gather food and eat it. Once our cells have enough fuel, they tell our brain to change our behavior again, i.e. we lounge around doing pretty much nothing until fuel runs out again. And round we go.

I agree with you. In the past few years, twice I enjoyed a cheat free period. 1st time was low carb, 2nd time was zero carb. I lost a decent amt of weight, but was not near goal. Both times "something" happened, and all logic, willpower, whatever, went out the window. I think my body said 'whoa, hold on, losing too much', and the eat whatever switch was turned back on

I definitely have two set points near my current weight. One is about 10 pounds lighter than I am now and the other about 30. Both points my brain messes with my ability to stick to things, plus I seem to have mini-stalls at both points. I think that I may have spent a lot of time in my teenage and early 20s at these points (probably swinging back and forth between the two). However, I am at a smaller clothes size than when I was here before low carb and lower than even when I got down this far before in low carb, I had more body fat. It seems the longer I do low carb, even if it's not continuous, the more lean body mass I put on. So I think if this theory is right, the set points might be in the brain rather than relying on some sort of fat cell signal, unless the signal is just about number of fat cells (which never decrease, right?).

Anyway, I am hoping to overcome that lower one because we're planning a trip to the States in a few months. I really don't know how big you have to be to get a seat belt extender, but I don't want one. Right now I am a UK 20/22 (back in the day I would have been lucky to zip up US 24s at this weight), and I'd like to drop down to a UK 18 before then. I carry all of my weight in my belly and chest (I could totally be on one of Taubes' slides where he shows the thin/fat people with my face blurred out showing my flat arse and relatively thin legs and my ginormous belly). More than the seat belt extender (as embarrassing as it is to ask for one), I don't want them to try to charge me for two seats ala Kevin Smith, although we won't be flying Southwest or anything. So, I really hope I can finally break through this stupid set point that's been holding me back for years.

Moggzy, it's not just about diet, it's about hormones. Remember the point of low carb is to control insulin which controls fat tissue? Well, like Taubes said insulin is not the only hormone that controls fat tissue. There's growth hormone, sexual hormones, epinephrine, glucagon, thyroid, etc. They all affect this "set point" as well. Look here:
http://www.why-low-carb-diets-work....eight-loss.html

The minnesota starvation study...

Okay, the men didn't start out fat. Suppose a typical subject was 160 pounds, with 20 percent body fat. I think that's pretty generous, given the time when the study was conducted. The guy from the study pictured in Dr Eade's blog here

http://www.proteinpower.com/drmike/...ways-a-calorie/

actually looks quite a bit leaner than that.

That would give 32 pounds of fat at 112000 calories. The starvation part of the study lasted 24 weeks. That's 168 days. That gives us an evil 666 calories a day if body fat stores were entirely depleted. In this case, semi-starvation was unquestionably better than actual starvation, since actual starvation would have meant death, probably long before the 24 week period was up.


These started out as healthy young men with relatively uncompromised metabolisms. I sort of think they were starving because they didn't eat enough. An overweight person with extra bodyfat on a low carb diet may have better access to their body fat than on a similar calorie high carb diet. These guys just didn't have that to draw on.

I didn't realise that I said it was just about diet. I was just mentioning that the set points are real in my experience, and they seem to be both a stalling point and a break of will power point. There is something going on in the brain, even if it's triggered by hormones, because I manage to justify my cheats really well. And it's ALWAYS the same weights (within a pound or two) regardless of how much lean body mass I have.

ETA: I also don't know if hunger is the same as what's going on with set points. It's not like I am exactly hungry or have an increase in cravings at that time. It's hard to explain and it could be something that is totally psychological. I get to a point and the stalling (even though stalls at other points are bearable--I was at the weight I am now for about 3 months without even being tempted to give up) and other factors come into play. I give in to my justifications.

I don't understand the point you're trying to make. If by better you mean that they would live longer on a semi-starvation diet than on an outright fast, then it's obvious. However, would you rather live longer but with constant and acute hunger that eventually makes you go crazy or live shorter but without the same hunger and without going crazy? In other words, would you rather have all your wits?

It's obvious why they were starving: They didn't eat enough food. That was the test after all.