My Paleo

So what ouputs are there in humans that have been proven different between individuals that point to efficiency variation?

A out of shape person and in shape person, both 170 lbs @ 30% fat, run a mile. In-shape person is less out of breath b/c their body uses oxygen more efficiently, which means their lungs have done less work, which means that fewer calories are expended for the same amount of activity. The actual difference in oxygen utilization can be quantified by measuring VO2 max.

So where is the energy going to? Is there a lower body temperature for example that would require less energy to maintain? The energy has to be accounted for somehow.

I don’t know, and clearly science hasn’t gotten it figured out either. The point I was trying to make is that when calories in and calories out are accounted for and show a deficit, and the body in question is not losing mass, then that is not a violation of physics. It is a reality that the calories in/calories out model can’t explain.

The calories in/calories out model is accurate for some people, just as the ideal gas law is accurate for some gases. But simplified models have limits, which is why someone saying, “I did it, therefore it’s possible,” means essentially nothing except that the model describes them accurately.

If a model doesn’t describe reality, as in the case of people who have diligently applied calories in/calories out to lose weight and have failed, you don’t deny reality. You come up with a better model.

" So what ouputs are there in humans that have been proven different between individuals that point to efficiency variation? "

Heat. The fine tuning of an individuals Krebs Cycle via uncoupling proteins.

More UCP = less efficient Kreb's cycle = more heat output = less ATP created per calorie consumed = reduction of surplus energy = reduction of energy storage = reduced propensity for fat storage.

"What you see on nutrition labels, menus, etc. already accounts for the systematic losses through our body's processing."

It seems overly simplistic to say that all people, all the time have the same percentage losses through our body

It may be that some diets result in less percentage being absorbed

"Mind. Body. Environment. Switch around the variables however you want, but if these three can't be synced somewhat successfully, you're likely fighting a losing battle."

I agree, Craig, but I would not necessarily assign them equal weight. IMO, if you master the mental aspect the body will respond, as it has for millenia. That is how people stayed alive in very challenging circumstances. It is in our genes. Same goes for the environment, again IMO. My personal feeling is that environment is the least critical piece of the puzzle, at least, IME. When I was still running, I never let environmental obstacles, be they physical, other people, work schedules, whatever, stand in the way. At times that proved very challenging, but there was always a way to circumvent them, simply because I had the mental determination to do so. Nor do I feel I am unique in that regard. I have known many others who responded the same way to environmental obstacles. In your case, based on what I know or think I know of you, I am relatively certain that the answer to your environmental situation lies squarely between your ears, and I'm betting you won't prove me wrong. I'll look forward to a post in the not too distant future that you have nailed that sub 3:30. ;=)

" So what ouputs are there in humans that have been proven different between individuals that point to efficiency variation? Higher Co2, less undigested carbs? Maybe "skinny folks" only digest 50% of the carbs that they eat? Could be, but I would think that would be measurable and fully researched."

A lot of the variables have been researched, Greg, but not all. For instance, the calorie content of fiber is still controversial and research is in progress. Many have assumed that fiber has no content, but there is growing evidence that it does contain available energy. How much has still not been settled to my knowledge. Another variable that may never be fully calculated is how much impact the thoroughness with which you chew your food has on the calories available to you from the food you eat. The possibilities are nearly endless, given the variability of food an individual eats and how thoroughly they chew their food. It would require a lot of p00p analysis to figure that one out, and I imagine there is not a long line of doctoral candidates in physiology queued up to do their thesis on this one. No glory there. That said, it would seem that in a controlled environment a liquid diet containing precise amounts of carbs, fat, and protein(think Ensure for instance) could be used to determine the basic efficiency of an individual's metabolism of the basic nutrients. Whether that has been done, and how applicable it would be in the real world, I do not know.

"Re reading my posts, i think i came across as uncaring, and that wasn't my intention."

Nah, Mike, you simply came across as Scottish….. ;-)

FWIW, I agree, for the most part, with the personal responsibility meme. I'm fat because of me, and only me, I take responsibility for it, and I'm taking responsibility for changing it.

But I also agree with Craig, what we do involves mind, body and environment. I believe that many of us get to a point, though, when we have the choice on how to influence these things to bring about the change we want/need. Many of us, not all of us. There are still far too many people (generally the poor) who don't have real access to grocery stores and decent food.

@ Jerry et al: "So where is the energy going to?"

Simple logic and observation tells me that there are unprocessed calories.

Basic metabolism. Human burn most of their calories to maintain bodily functions, very few with exercise, and the human body is very good at absorbing them if everything is flowing right and eliminating wastes. Just (IMO) delicious calories are readily available thanks to our processed foods industry, so most ingest more than they burn. That's why a larger person can lose a lot of weight – they burn more calories to start with, then add some exercise to move that mass, and weight loss start unless the person starts taking in extra calories to deal with hunger, …. plus joint issues, and other stuff that's really in the M.D. /dietician lane. Also with carb deprivation long-term or any extreme diet, at least consult a pro (MD, RD, etc..) about it as there are some biochemical consequences. It is physics at one point but also connected biochemical pathways trying to maintain a balance with some potential for bad.

To understand how carbs work in the body then it is important to know how the body actually uses those sugars. Becoming T2 diabetic gave me great insight into this because I did a lot of reading to wrap my head around what was going on in my body… this also helped me to understand how the body works in a non-diabetic.

Simplified it's like this…

A normal person without excess weight is insulin sensitive. When they consume carbohydrates the body produces insulin to help the cells use the sugars. Think of the insulin as a key to cells with a big padlock on them. The insulin unlocks the cells and they use the energy.

Obesity causes the body to be less insulin sensitive so when carbs are consumed the cells remain locked because not enough insulin is released and used by the cells. They remain locked and the glucose gets dumped into the bloodstream rather than the cells. That's why Type 2 diabetes is practically epidemic in our countries and can be reversed with diet and exercise. Now Type 1 is a totally different beast so I won't even go there.

The body uses insulin to restore muscle glycogen after intense physical activity. That's why many athletes carb-load the day before intense training or an event. You'll often hear of runners using something like chocolate milk as a recovery drink.

I remember being over 360 pounds. When I would try to lose weight I could drop 20 pounds in a week because the caloric burn was so great when I did anything… walking, hiking, etc. I lost weight more easily despite hormonal issues. The same activity now, when I am a mere 30 pounds from being a perfectly regular weight, burns far less calories. When you are obese it takes far more energy just for you to exist. That's partially why you see such dramatic weight loss in shows like The Biggest Loser. I used to laugh when my "skinny" friends would say that they are "so fat" and "can't lose this 10 pounds". It's a lot more work in some ways than it was when I was stage 3 morbidly obese.

A healthy, lean body, uses calories more efficiently. When we do cardiovascular exercise (hiking, running, etc) the muscles make and use energy. This is very dependent on force, movement and intensity. There is a compound that our muscles produce too. It is called ATP (what it stands for eludes my brain at the moment). Muscle glycogen also provides more glucose during high intensity workouts but stores can wane when doing something for a long duration… and that's why snacking on some carbs while hiking can be helpful.

I don't know if that was of any help or not… hopefully it made sense.

Adenosine tri-phosphate used in muscle and other cells. Having a metabolic problem like diabetes obviously requires a physician, who will attempt to have the patient control insulin and carbohydrate levels. ATP can be generated from carbohydrates and lipids so the muscles try to have a constant supply of it + oxygen At a certain level, you get back to conditioning and exercise as the body needs oxygen to generate ATP.

"When they consume carbohydrates the body produces insulin to help the cells use the sugars. Think of the insulin as a key to cells with a big padlock on them. The insulin unlocks the cells and they use the energy."

The cells could use the energy to do work – as in exercise

or they could use the energy to produce heat

Does an overweight person, that lost weight, and is now being more efficient with calories and thus more likely to regain weight, is that person colder? That would explain where the calories are going. There is something to be said for the physics conservation of energy argument.

I can't say for sure whether a person is colder or not… but I do find I feel cooler even at rest than I did when I was obese. I figure it is because I have less insulation now… lol.

I do know that I release less CO2. How do I know this? Mosquitoes (and a friend who's a bug guy at a local university).

You see, mossies (as I like to call them) are attracted by the C02 in our breath. That's why those propane patio mosquito controllers work. The bigger/fatter you are the more CO2 you expel… and that's why I was always a smorg for the bloodsuckers. I've noticed a dramatic decrease in the mossie attacks since I've lost weight.

I definitely run a lot colder now than I did even when I was at a healthy weight (but with a higher body fat percentage). Like Laurie, I primarily contribute it to lack of insulation, but the reality is I have no idea why I run colder. The worst is my hands and feet which are cold even now with it ~ 62 F in my house. Also, I run very hot when I initially go to bed and when I exercise.

FWIW, I don't believe that someone who was once overweight and is now fit is any more likely to become overweight again than someone who has never been overweight (medical conditions aside). Look at NFL guys. They get very used to consuming a massive amount of calories to maintain their size and fitness regime. But if they get injured, can no longer compete, and subsequently fail to decrease their caloric intake they are highly likely to end up considerably overweight.

My feet are always cold but part of that is that I have neuropathy. My hands… freezing all the time. I'm so cold when working at the computer that I have the thermostat in my office at 71°F and I am wearing two layers which include a heavy weight sweater. I freeze when I go to bed… to the point I am using a 750 fill down bag as my summer bag and I use a down duvet and heavy blanket at home. I noticed this summer that I needed a wrap or jacket in the evenings although it was in the high 90's still.

My spouse is always hot, unless he's ill so there is a constant thermostat battle around here.

Chris, you might be surprised at how many over weight folk don't eat any more than "regular" folk. It isn't always about eating tons of food, ie calories. The lack of moving and or a lethargic metabolism (from not being active) can lead to it.

And why do you run colder? It has NOTHING most likely with your body weight. It is simply how YOUR body functions! If you are cold you probably need to get moving more :-P Pretty simple when you look at it – it is your body telling you two things biologically: you don't move you will freeze or go eat and get the furnace going inside. Don't look any deeper, it isn't a deep question.

Or as my Mom would say when I was young "If your cold, go do a load of dishes". That worked pretty well. If I am cold now, I do that, go for a walk or sit next to my husband "The Heater".

PS: By BMI charts most, if not all, NFL players are "obese" due to their physical size (height and weight) because of the sheer muscle mass they carry. They can weigh 300-350 lbs where the charts say they should weigh 200 at most – muscle mass is what throws the BMI chart off quickly.

And PS2: 62* IS COLD. Just in case you hadn't noticed. LOL! Hate to break the bad news, but 62* is only considered warm by a few folks ;-) No wonder you are cold…hah!!

Sure, there are several factors that make a person cold or warm . Metabolism, age, thyroid….AND amount of fat. That cannot be dismissed. I have several heftier girlfriends and they run much warmer than me. I gain an average of 5 lbs in the winter and it really helps. Fat is great insulation, aging….not so much.

"And PS2: 62* IS COLD. Just in case you hadn't noticed. LOL! Hate to break the bad news, but 62* is only considered warm by a few folks ;-) No wonder you are cold…hah!!"

What, are you kidding? 62 degrees is downright balmy! ;-0

Actually, and of course, it all depends on the 'normal' temps. 62 degrees in summer is fricking cold! 62 degrees in winter is downright warm!

Chris has a low bodyfat % and a high muscle to fat ratio. He will feel colder than someone who simply has more fat.

I have proven this to myself in the 'field.' As I got into better shape suddenly my sleeping bag did not feel as warm to me. I gradually went from a 'warm' sleeper to a 'cold' one.

Careful David…that almost qualifies as non P. C.
;)

Just speaking for myself, I guess, as absolutes are rare. When I gain a few pounds I stay warmer. When I lean up I get colder. Everything else stays the same. Fat works as an insulator for me. Makes sense to me.

Sarah, if you go back through this thread you will see that I was once "obese", even morbidly so by some opinions. I got there by both lack of activity and overeating…..so I put on a lot of weight quickly (and have the stretch marks to prove it).

It has nothing to do with my weight and I suspect everything to do with my veins being quite exposed due to lack of insulation. Nurses love me for injections and IVs though. I'm far from lethargic and eat more than should be necessary for someone of my build and weight. Never the less I generally stay cold and don't put on weight.

BMI charts are worthless for all but a very tiny part of the population. You seem to agree. I completely ignore them and rely on being at a healthy body fat percentage, although that too can be off depending on where the fat is carried and what type it is.

Temps – I guess it varies some.

Here's my personal example-

Back in 2007 I did a trip in the Smokies. It was November and temps got in to the low teens. My sitting around camp clothing was softshell pants, light gloves, a wool base and MB Thermawrap jacket, and a fleece beanie. I was toasty. I was somewhere in the 165-175 range and around 15-18% body fat. By most charts, I was in a healthy range with body fat and for the most part with weight. At the time, I was no where near as active as I am these days.

I've been in very similar conditions since getting down under 145 (135 today) and under 8% body fat (generally 6-7%). By a lot of charts I'm now considered underfat (whatever that means). Even in to the 20s I now require down pants, down booties, and a down hoody. I have yet to find gloves (or combinations) that keep my hands warm. The clothing ensemble generally keeps the cold tolerable but is far from toasty. The next trip I will be taking a Rab Infinity and likely some of Ben's 3.5 oz fill down pants to see how that goes. I also plan to start using a sleep system rated closer to 0F than the 15F bag I have now. I'm hoping that will work, but I'm not holding my breath.

BMI charts can certainly be misleading. However, I used BMI as a gauge to see where I was at the time and what would be an ideal range for me…. seeing as I was mostly fat at the onset of my journey to be a healthier person. BMI, gave me a goal to work with.

Both my family doctor (who's a Sport Medicine doc as well) and my nutritionist have suggested that I stop and assess when I am within about 12-15 pounds of the BMI chart ideal for me. I found that curious but it makes sense when I am doing activities which use the largest muscles in my body and have the potential for muscle gain. I have never looked at percentage of body fat other than with a mirror… and that was telling enough.

I started using a tape measure rather than a scale because of this as well. The scale isn't so accurate. While the running has only taken off 1/2 to 1 pound a week over 6 weeks I've lost inches off the waist, arms, hands, chest, and neck while my thighs and calves have increased slightly in size. That's a more telling story for sure. The scale lies because glycogen, hydration/dehydration and many other factors can influence the number greatly.

>> …so I put on a lot of weight quickly (and have the stretch marks to prove it).

I call mine racing stripes. And I agree that BMI is a very general guideline that only applies to some. At 175 pounds and 5'10", I had about 5 – 7% body fat and was "ripped" (wish I took more pictures back then). According to the military, I was still fat.

>"Both my family doctor (who's a Sport Medicine doc as well) and my nutritionist have suggested that I stop and assess when I am within about 12-15 pounds of the BMI chart ideal for me. I found that curious but it makes sense when I am doing activities which use the largest muscles in my body and have the potential for muscle gain."

Laurie, I can imagine that being particularly true when you're losing a lot of weight while doing a lot of exercise. Inside of a big, active person is a lot of muscle. I've found some really big guys (280-350 pounds) in construction can do and lift things I (170-180 pounds) can't approach. They don't lift weights, they don't work out other than on the job. Just moving around with that extra weight builds a lot of muscle.

There may come a time when you have a decision to make – keep that muscle, or not. And to keep it, you might need to do more weight-lifting type exercise. Or hit the hills more or carry a non-UL pack even while dayhiking.

My wife scratches her head each time she cuts back on training (competitive rowing) and loses some weight but it makes sense to me. If calories in = energy expended, but exercise decreases, then 9 pounds of muscle can turn into 4 pounds of fat and your body will have the same stored calories as before.

I'm just hovering around 190 lb at the moment and I am 6 feet tall. From a BMI standpoint the recommended weight would be about 160 lb and I have to wonder if that would be too low considering that I am striving for an athletic body and not trying to be model-thin. We'll see how it progresses.

I've always had very strong legs and that was definitely due to carrying around such a large torso. Most of my weight was from the hip up unlike many ladies who have a larger posterior, mine was more of an upside down pear. Thanks for the weight suggestion. I've already started integrating weights into my training. One, keeping good muscle tone is important because those larger muscles burn more calories/fat and for toning purposes. And, I've increased the lean protein in my diet as well. One of my closest female friends is a power lifter (she freaks me out a little – lol) and while that's not my thing, I've learned a bit from her.

My solution for day hikes… a 19 month old baby girl who weighs 23 pounds in a back carrier… lol.

Competitive rower, eh? I think people are surprised to know just how much energy and force is expended with activities like rowing and sculling.

"BMI charts are worthless for all but a very tiny part of the population."

You are right Chris!!
I am too light – doing a lot of cycling and hiking and I have been very light all my life. According to the World Health Organisation my BMI is "lowering my body performance" but in fact I have alays been healthy and my doc just says the same.
I don't even feel cold very often…
I think it's more about how your body is built and how you changed that. People who have had the same BMI during their whole life feel a lot better than others who suddenly gained or lost lots of pounds. No matter if your BMI is a little too high or too low…
And you also see that on the trails: Backpackers don't look like models but just like "I feel good with what I have".

I'm 6'1 and now 200 lbs…My BMI would say that I am obese…not so.

Doug this diet sure sounds like a diet us diabetics use. Good luck to you and I hope to see a thinner Doug in Feb.

Good for you!