Size of internal organs in obese/morbidly obese people

If a person gains weight and becomes obese or even morbidly obese, do the internal organs increase in size as well? If an obese or morbidly obese person loses much of the weight, do the internal organs shrink in size?

In my experience, post-mortemwise, the internal organ liable to increase most in size, largely through fat deposition is the liver.

The heart will tend to be enlarged, partly through hypertrophy and also through dilatation. Overall weight could be as much as doubled in marked obesity but similar weights can be seen in other settings.

I’ve seen (but fortunately not had to do) an autopsy on a 600+ pounder. The internal organs in general are fairly normal in appearance. Most of the weight is deposited in the body wall and extremities.

A nurse I knew insisted that organs are always the same size regardless of the size of their owner, regardless of body height or weight. That is, the hearts of really huge and really tiny people were all the same heart size, and the kidneys always the same kidney size, and so forth. I asked what other kind of stuffing made up the difference for the largest people, if the organ sizes were small enough to fit into the largest people. No argument I could think of could budge her from her position. She insisted I didn’t know what I was talking about, whereas she assisted in surgeries and had other relevant experiences.

Now, of course, for people of normal stature with morbid obesity, the “stuffing” would include a great deal of fat.

But if you were to study the organ sizes of professional basketball players and professional jockeys or gymnasts, none of them with a great deal of body fat, it’s hard to believe there wouldn’t be a difference.

There must be a measurable difference in organ size because the organ transplant teams must match by size as well as other factors.

I would imagine obese people have enlarged hearts, because of the lack of exercise the heart has to work harder.

There’s a match for maturity, in that, you can’t put an adult kidney in a toddler, but the match for “size” is mostly be maturity, isn’t it? once a person reaches adolescence, they can handle any adult organ?

I’m basing this on some general knowledge, but also some specific knowledge of a teen who was a match to her father for a kidney, but couldn’t receive it till puberty. At that point, she was about 110lbs., and 5’1 to his 180lbs & 5’10, but she could receive, and she couldn’t the year before, and the same weight, and just an inch shorter.

I could be wrong. It’s a sample of one.

Heart size is linearly correlated with body size.

Sex, height, weight, and age significantly affect the normal heart size.

Liver size is correlated with body size.

Thank you! See? See??? I knew I was right!

There’s a BBC video available on youtube that documents the autopsy of an obese woman. It’s NSFW but very clinical and respectful. The pathologist goes into detail about how the obesity affected some of the organs. You can find it using ‘Autopsy on an Obese Woman: Obesity Post-Mortem.’

These references are not particularly impressive, as far as supporting the thesis that obesity leads to organomegaly.

The third one shows that log of liver weight vs log of body weight is linear over the range of body weight from 3-30 kg. There is no mention of obesity here per se, and it seems to simply reflect that adults have larger livers than children.

The second reference says: “In a further linear regression analysis with stepwise selection, the influence of BMI and BSA was evaluated in addition to weight, height, sex, and age. BSA influenced all analyzed cardiac cavity dimensions, whereas BMI revealed no statistically significant influence (data not shown). Thus, in a third linear regression analysis, weight and height were replaced by BSA” BSA (body surface area) is the square root of height in cm times weight in kg. For a given weight, a taller person will have a larger BSA than a shorter person. They point out that BMI is not a significant predictor. This goes along with the notion that taller people have larger livers than shorter people. This should not be surprising: make a person twice as tall, and if everything scales equally (which it doesn’t), the taller person’s liver will be eight times the volume of the shorter person’s. But make the taller person twice as heavy, and the liver does not go up nearly as much in size.

I haven’t had Jackmannii’s experience in pathology, but in surgery I’ve had my hands in a lot of living patients. Fat deposits tend to be on or around internal organs; the organs themselves don’t get bigger. A skinny person’s mesentery (the tissue band that anchors the intestines and carries the blood supply to them) may be a quarter inch thick on average, membranous looking, and flexible, while that of a morbidly obese person may be two or more inches thick, rubbery, and opaque. The bowel may have nodules of fat along its sides and antimesenteric edges. The intestine itself, though, doesn’t double or triple in size. A skinny kidney might have an inch of fat around it, and an obese kidney has more, but the kidney itself doesn’t swell.

A Frenchman by the name of Tarrare who had a compulsive eating disorder was found to have an enlarged esophagus and stomach at the time of his death. He died in 1798 so the exact accuracy of the autopsy results should probably be taking somewhat skeptically.(The article I linked doesn’t actually say if he was obese at the time of his death; I just assumed he was do to his obsessive eating.)

Also a disturbing part of the article: