The body needs bile to digest fat, right? And it only has a certain amount of bile. That means if you eat excess fat, it won’t be digested.
How much fat is that? Is it possible to eat that much? If so, won’t it be healthier to pig out occasionally, rather than eating more every day?
Are you willing to monitor and understand your stools?
If so, being that every individual is different, there are ways to get a general sense of whether your body is processing a general percentage of what you eat.
Professionals have studied stool samples to determine how, for example, calcium (not supplements) can block fat absorption.
In very controlled studies, you can find out some things about how your body absorbs fat.
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Bile enhances fat digestion, but said digestion is not absolutely dependent on bile. Much emulsification of the ingested fat takes place just by mastication and gastric digestive activity, which break up the fat into small globules and coat it with phospholipids. Later in the duodenum, bile adds more phospholipids, and further enhance the formation of digestibly sized particles.
What is really needed for fat digestion is lipase, which breaks the fat down into monoglycerides and fatty acids. This comes from the pancreas.
When the system works well, 94% of ingested fat is absorbed. The remainder passes thru the bowel and exits eventually.
Overall, the amount of absorption is thus dependent on degree of chewing, concentration of fat in food, length of time spent in stomach, relative amounts of bile and lipase added to the mix, length of transit time thru the bowel, bacterial flora of the bowel, and probably atmospheric pressure and phase of the moon for all I know.
It’s certainly possible to overwhelm one’s ability to digest about 94% of fat eaten, but where the tipping point is for each individual is quite multi-factorial. But when one passes the tipping point, it’s generally easily noticed, as stool becomes very gassy, greasy, loose, floating, and incredibly foul-smelling. Most folks experience this sort of stool due to dietary overindulgence at least once in college.
But go ahead a try it! Standard protocol is to do a food diary tracking closely all the fat ingested for 72 hours, then collect all stool excreted for 72 hours, store it, and when done, take it to a lab for analysis of total fat content of the stool. Subtract stool fat from total fat, and you’ve got percentage absorbed at that level of intake! Then up the fat intake, and do it again.
Oooooh! I think I found my date idea!!! 
Thanks QTM!
I don’t have a cite for this but I heard on a documentary that Antarctic explorers burn through more calories than they can possibly eat in a day and supplement their diet by guzzling olive oil. They reportedly can absorb 6-8000 calories maximum while burning even more than that. But I might have the numbers wrong.
Everything, but just one more waffer-thin mint.
Wow thanks, I thought that was caused by spicy food.
Spicy food can stimulate some individuals’ bowels so much that with the decreased transit time, less fat gets absorbed.
Lots of things can influence the situation.
That sounds like a lazy-man’s way to lose weight. Eat all the fatty things you want, but coat them liberally in Tabasco first! 
Qadgop, yours would be the most peculiar “Ask the…” thread. Which you might consider doing.
You mean like Ask the maximum security prison physician? That thread is nearly 10 years old now. 
well, u always see those steakhouses with the ‘eat this steak in 15 minutes and get it free’ offers, typically 72 or 80 ounces. I don’t know if red meat has a lot of fat, but certainly > chicken. Any1 out there win a steak like that & willing to divulge what happened the next porcelain sitting?