Active Low-Carber Forums - View Single Post - Rapid Weight Loss Causes Gall Stones??????

Fasting can do funny things. My first full day fast, I woke up at 1 in the morning and vomited yellow bile. I was already on a fairly high fat diet, and ate very regularly, I sort of suspect my body had a rhythm of bile secretion that was connected to my usual eating times. Or something. This never happened again.

What Dr Barry's saying--I think he may be taking some license in that he thinks our "intended" diet is one of saturated fat, so the digestion of saturated fat is what bile is "for."

Quote:

The effect of polyunsaturated fats on bile acid metabolism and cholelithiasis in squirrel monkeys.
Melchior GW, Lofland HB, St Clair RW.
Abstract
Squirrel monkeys (Saimiri sciureus) were fed diets containing safflower oil, butter, or coconut oil and 1 mg cholesterol/cal for 15--17 mo to examine the effect of type of fat on cholelithiasis and bile acid metabolism. Controls were fed low cholesterol diets containing an isocaloric mixture of the three fats. Cholic acid fractional catabolic rate, pool size, chenodeoxycholic acid pool size, and total bile acid pool size and excretion rate were estimated using a modification of Lindstedt's isotopic turnover procedure. The animals fed the safflower oil diet had the highest incidence of cholelithiasis (9/10) when compared to those fed butter (3/7) and coconut oil (1/7). Animals consuming the low cholesterol control diet did not develop gallstones. The butter- and coconut oil-fed groups had significantly (p less than 0.05) expanded bile acid pools when compared to controls, and the butter-fed group had a significantly increased (p less than 0.05) cholic acid fractional catabolic rate. The safflower oil group had the smallest mean bile acid pool and the highest mean lithogenic index of the cholesterol-fed groups. It was concluded that the safflower oil-fed animals had a higher incidence of cholelithiasis than the butter group because, unlike the latter group, they did not compensate for a high cholesterol intake by stimulating bile acid synthesis. The animals consuming coconut oil apparently did not absorb cholesterol to the extent of the other groups and as a result their bile did not become saturated with cholesterol.

Squirrel monkeys... but perhaps some relevance to human beings, and the evidence that a low calorie diet that is also low in fat might increase gallstones.
In the monkeys, at least--saturated fat increasing bile production versus safflower, and this preventing gallstones on a high cholesterol diet is interesting, since their natural sources of dietary saturated fat would also be their natural sources of dietary cholesterol.

If it's normal to dispose of some excess cholesterol through the gallbladder, and if bile acid is needed to be above a certain level to prevent stone formation in this situation--you could see, in a long-term adaptation sense, why people on the SAD diet might develop a problem on a low fat diet, even though there are populations on extremely low fat diets without this problem. If bile is needed for several purposes, but most of your life, you've eaten enough fat that the signal for production from the fat consumed is sufficient for all purposes, the body becomes a poor regulator when that signal is absent. That is, a fasting creature still needs sufficient bile acid to prevent stone formation, but a lifetime of very little fasting means that the genetic/physiological programming for that state never quite got unpacked. Blah blah blah epigenetics and appropriate sciencey stuff.