SubscribeThe Science of Obesity
Recently, the National Geographic Channel has been airing the documentary “The Science of Obesity”, which explains the various ways that obesity impacts the body and how “Francis” -a 28-year-old male who is 5 foot 8 inches tall and weighs 500 pounds copes with day-to-day activities.
Some interesting facts from the documentary:
From the years 1960 to 2002, the average weight of American men and women has increased by 24 pounds, but our average height has only increased by one inch.
Over 9 million Americans are considered Morbidly Obese. This classification is based on the body mass index or BMI. A healthy BMI is between 18-25, while a BMI over 30 is considered obese. Morbidly obese is normally a BMI over 40. Francis had a BMI of 76.
BMI, however, is a flawed indicator of health. Recent research shows that waist circumference is a far more reliable indicator.
The average human has between 25 to 275 billion fat cells, but the number of fat cells has no correlation with weight gain. As we know, the reason a person gains weight, it is because the fat cells expand or get “bigger” to absorb more fat.
As most people know, obesity is extremely stressful on the heart. One reason is because the heart has to pump a much higher volume of blood in an obese person.
How much?
A 190-pound male has approximately 12 pints of blood, while morbidly obese Francis has over 30 pints of blood pumping through his body.
Another obstacle to losing weight for obese individuals is the relationship between weight gain and lowered lung capacity. The more body fat that accumulates in the body, the more fat deposits in the chest wall pushing against both the lungs and the diaphragm.
This lowers the ability of the lungs to expand and bring in oxygen. The end result is that obesity makes it more difficult to exercise and recuperate from exercise.
Finally, the average stomach can hold approximately 3 pints of food from a meal. In those who overeat, the stomach will often stretch to hold up to 6 pints of food. (This is approximately ¾’s of a gallon!)
If you enjoy learning about the physiology of weight gain, then “The Science of Obesity” is definitely worth watching.
A 190-pound male has approximately 12 pints of blood, while morbidly obese Francis has over 30 pints of blood pumping through his body.
I don't know why, but I find this fact incredibly cool. Yes, it's bad to be obese, but extra blood! That's just so neat!
ReplyWhen you see the statistics like that (about the changes to your body if you become morbidly obese), it really becomes clear why it's so hard to lose weight.
ReplyThanks for the tip, I'm going to see if that is on in my area. I get really motivated by health rather than just looks and I'd love to watch this.
ReplyIn my physiology class in college, we did an experiment to figure out why they always take one pint of blood when you donate. We figured they should take it based on body weight, since heavier people have more blood. It IS kind of neat, if you think about it. But what ISN'T neat is that the same size heart has to pump all that blood, which stresses it out a lot. It's like having two pumps...one pumps one gallon of water through 10 feet of pipe. The other one has to pump 3 gallons through 30 feet of pipe using the same amount of power. Which pump wears out faster?
I'll have to see this show on TV when it airs again...it might be kind of interesting.
ReplyObesity is a disease. Not far from alcoholism, drug abuse or anorexia. The only difference is alot of times people can hid their "problems". When you are obese - you "cannot run and you cannot hide". Too bad alot people treat fat people like shit.
ReplySounds like a great documentary, I'll be sure and watch it! I like the mention of how BMI is a poor indicator for health at best. Best measure is the mirror, that will tell you if someone is fat!
ReplyThis show came on over a month ago.
ReplyScary point, Spectra. Yet one more reason for everyone (not just Americans or visibly overweight people) to get up and get moving.
ReplyMoral of the story: Don't name your kid Francis, or he will be fat.
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ReplyObesity isn't always a disease, it can also be a choice. Why do we go around making up diseases for problems we have? Consciously choosing to do something that is detrimental to yourself in some way does not mean you are sick. Misguided, ignorant, or even bored, perhaps, but NOT stricken with an indomitable disease that cannot be overcome.
Obesity is a problem that effects everyone. If not physically than financially. As insurance companies are now paying for various stomach reduction surgeries the end result is higher premiums for all of us. Why not urge everyone you know to take charge of their health now. If you're still breathing there is hope. www.goodnlean.com has a fantastic program that is natural and organic, easy to do and personal coaching through the system is FREE. I know I've done it and it works!!!!
ReplyThe problem with your example is that the larger volume of blood does not require a higher rate of transfer (pumping) through the heart....the surface volume of the body has increased, and the volume of blood has increased, but the body is a closed system and the volume of blood pushed (pumped) through the heart each minute doesn't have to increase to maintain the system flow. In fact, a larger person with an increased volume of blood - blood having to flow through a larger area of body space - does not automatically translate to more blood per minute pushed through the system.....nor does it translate to an increased beats per minute to move the blood, or increased pressure to move the blood....pregnant women prove this - their blood volume increases 50% in pregnancy and the vast majority do not experience increased heart rate (beats per minute) nor increased blood pressure.....nope, their tensive stats remain stable throughout for most.
That's not to say that the increased volume or area to move the blood through cannot affect one - it can and often does - but it's not because of the volume of blood or area to move blood. So the idea that a larger body has to move significantly more blood per mnute becasue it's bigger is inaccurate.
ReplyWe also have to remember that the government changes what obesity and overweight is from time to time. With the addition of the BMI (which is complete garbage) imho things got even worse. They also drop the BMI standards from time to time. No one knows how we are supposed to evolve or what "normal" weight should be. Stats are a funny thing.
ReplyI have to change the way I eat as eating a lot is what I have been doing for so long and it is time for me to correct this mis take. Correcting this eating habit is a must as it has affected my life. Thank you for this post as a personal trainer can also make the same mis take even while still being really fit.
ReplyI think it's complete BS that insurance companies are covering gastric bypass surgeries. IMHO, if you are so overweight that surgery is indeed your only option, you should have to pay for it. It's a risky operation and it doesn't guarantee that you'll lose the weight (I know a woman who had the surgery done and got down to 140 lbs. Then she started to "cheat" the surgery and managed to gain back up to 250 lbs again.). I think surgery should be reserved for people who seriously CAN NOT exercise and are suffering from severe side effects like edema, apnea, diabetes, etc. In all other cases, it's pretty much an elective surgery. I wouldn't ask MY insurance company to cover a breast augmentation, so I don't see how it's fair that other elective procedures are becoming covered so people can take the easy way out of losing weight.
ReplyI think that the heart does not stay the same size with increased body mass, but there is left ventricular hypertrophy and this makes heart failure a more significant risk in these individuals. :-(
ReplyI don't think the operation itself is bad; for some people I know it IS the only option. I'm just saying I don't want to pay for other people's operations when they aren't absolutely necessary. I just think people who need the operation should be paying for it themselves and not passing the cost on to the rest of the population.
ReplyI'm fat. Too many calories in & not enough calories out..No secrets, no pills. It is all math. No one makes me do this. It is Nobody's fault but mine.
ReplyI agree with people paying for the operation to a point. Maybe a sliding scale type of payment with a government co-pay for those without funds. I would imagine, from a business perspective, that a healthy person is a lot less costly.
ReplyVery interesting about the left ventricular hypertrophy. It makes sense to me...the heart would naturally want to adapt to become stronger. And while the rate of flow doesn't necessarily have to increase, you can't deny that one "heartbeat" will push more fluid further when there is less resistance (ie, fewer blood vessels) as in a thin person vs. when there is a lot of resistance (ie, more blood vessels) as in a fatter person. I'm guessing this is why a lot of obese people have circulation issues. Extra fat puts stress on a lot of systems; not just the circulatory system. You get problems with your breathing, joints, lymphatic system, etc.
And Dr. J.--I like the "sliding scale" idea for paying for surgery. Some people DO really need the operation, but it can be a vicious cycle. Someone who desperately needs the surgery probably can't get out of their house to have a job, so they probably CAN'T afford it. In that case, I would agree with a government-paid co-pay, but for the average Joe or Jane that is just over the BMI criteria (40) and thinks the surgery will finally help them keep weight off, I think they should pay for it themselves. When I was overweight, the surgery was just catching on...Carnie Wilson had it done and a lot of people wanted her results. I read about some people who actually GAINED weight on purpose so they'd have a BMI of 40 to qualify for the surgery. That's taking it a little too far, IMHO. I think if people realized how much health care actually COSTS, instead of just figuring insurance will pay for it, maybe we'd be a little more conservative with our health.
ReplyAnd now the good news! Spectra, I got to talk to a heart expert today and she said that in runners like us, the heart does not enlarge! With our lower blood pressure and less resistance, our hearts are not enlarged but more efficient with higher stroke volume per beat, higher ejection forces, and a lower heart rate also. Of course we could be run over by some truck while running, but our cardiovascular system will be healthy lol
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ReplyThat makes sense. Runners make their circulatory systems "squishier" by making those blood vessels stretch a lot, so it makes sense that there would be less resistance. My husband (a mechanical engineer) told me it's sort of like the difference between water flowing through a floppy latex tube vs. a metal pipe. There is a lot more pressure in the pipe because it's stiff. Good to know that my circulatory system is adapting in a GOOD way to running, lol. If I had a dime for everyone that told me that "running will make your heart wear out faster..." I'd be so rich.
Dr.J,
Hm! My partner was told by her PCP to see a cardiologist because of an unusual ECG. The cardio guy told her that she had an "athlete's heart", eg, enlarged by exercise (he actually said it was longer). He wasn't alarmed by it - he told her she was just fine. She's not a huge runner - she logs 20 or so miles a week - but she's fit. She's 5'4", weighs under 105, and has good upper body strength. It all made sense to me! So, I'm surprised to hear your cardio guy say that hearts aren't enlarged by exercise.
My weirdness is higher blood pressure - 130s systolic, 90s diastolic. I'm reasonably fit for a guy in his fifties, although I don't have any self-delusions, living here in triathlete heaven (my trainer's trainer is Paula Newby-Fraser, woof) I run 40+ miles a week and crosstrain. I'm reasonably fit for a guy in his fifties. My resting pulse rate when I get up in the AM is in the high forties, and mid-day it is in the low fifties.
So, I find the whole circulatory system vs cardio a big mystery.
ReplyIt's obviously not my area of expertise, so I'm just guessing that the heart's response to activity depends on blood pressure (resistance), body mass (especially muscle mass), and genetic variability.
ReplyWhen I was in my physiology class in college, we did EKGs on each other and at the time, I was logging around 40 or 50 miles a week of running. My resting heart rate is something like 50-60 bpm, so when it came to be my turn for the EKG, the prof used me as an example of having athletic tachycardia. I'm guessing that has to do with the increased stroke volume and the low resistance. I know my blood pressure has gone down considerably since I started running...hypertension runs in my family, so I started running instead of waiting to go on medication later on. I'm pretty sure exercise has a bigger effect on blood pressure than just about anything else you can do.
ReplyRegardless of it all, "weight loss" is a misnomer. Fat loss while maintaining (or gaining, if desired) muscle is what contours the body. The "tried-n-true" methods of proper/good nutrition, regular exercise, proper amounts of sleep and we'll add a dose of meditation/R-n-R/etc. (or whatever you prefer) for "play". (see Fat2Trim.com)
ReplyDrastic measure may be necessary on exception....But if the "national girth" keeps growing, that exception will become the rule...So will chronic illness/disease!
When will the humans ever learn?!
OK, Quito, I ran into my 'heart expert' today, and maybe she is not as expert as thought :-) At any rate, it looks like there is some enlargement with the athlete. In the studies I found, this athletic enlargement is not pathologic in nature, and I believe this. It is interesting that, in endurance trained athletics, the enlargement is not as great as in strength trained athletes. As I said, lean muscle mass has a direct effect on heart size. That's my story and I'll change it tomorrow if I want to, but I hope I won't have to :-)
ReplyOk, i know i am no small guy, Im 6'4.5" and 255 pounds, but i do do serious weight lifting and cardio 4to5 days a week, and am in better "shape" than most people who call me fat ((which im not, i have a 35inch waist(which makes it hard to find good jeans)so i dont rly know why people would call me fat)). BUT, even at saying this, iknow i could stand to lose more weight and am currently doing that. But having that, i also want to say that i dont believe obese people have any excuse for being as big as they are. I have heard it all, i dont have time to workout, and all that bulls**t, because weight loss IS NOT as hard as people say it is, and i hate the fact that FAT people are babied, not by everyone, but by many, beacuse they are fat, and people take pity on them, and it is totally undue pity. If you truly wanted to lose weight, you would eat less and workout, you dont have to lift or run, u could simply go outside, or to the gym and walk for a while. Its that easy. I would also like to say that when people say that being FAT is a disease, i want to smack them, because it is called pure laziness.
Now, after my little rant(and i know thats what it was ) i would like to apologize to anyone who ACTUALLY has a MEDICAL ILLNESS(no, being lazy and eating like a pig is not an illness)that causes them to be overweight or obese i have alot of understanding in ur respect, bcuz i know personally how hard that can be, it affects everything from you personal, to academic, to athletic life and if you work to beat your illness, then i have the greatest of respect for you.
ReplyWith exercise, the heart grows just like any other muscle. It adapts slowly - the blood vessels supplying it develop more as it grows bigger, to ensure the new muscle is properly supplied.
With ventricular hypertrophy, the new muscle doesn't form in an organised manner. Specifically, because of high blood pressure present ALL THE TIME, compared with exercise which is NOT happening all the time, the muscle grows faster than a new blood supply can develop. Thus the risk of heart failure and heart attack.
I just made that up, but it sounds plausible.
As for fat people, the main reason people (i.e. society) dislike them is because being fat is physically unattractive. Aside from the unattractiveness of being fat, theres nothing actually wrong with being greedy - if eating lots of food had no effect on attractiveness, it wouldn't be seen as a bad thing.
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