In general, carbs break down into glucose for consumption... which isn't the worst thing. Fructose (about half, or more, of most natural sugars) is only able to be processed by the liver and usually in excess of what can be metabolized meaning a build up of fatty liver. This has other side effects leading to metabolic syndrome/diabetes/heart-disease.

A big issue is that many people eating low fat actually don't get enough protein or especially fat. Most natural sources of protein (particularly meat) come with around 0.5g of fat per 1g of protein. Lean sources are quite a bit lower. Without enough fat, many will see issues with their gal bladder over time. There's also more insulin response to protein without accompanying fat.

Another issue is refined vegetable oils have more linoleic acid, which leads to more carb absorption in general.

In general, most people are now getting too much carbohydrate, often not enough protein, and almost always not enough fat.

> Without enough fat, many will see issues with their gal bladder over time

Wait what? I was under the impression that most gal bladder issues came from fat, not from not enough fat. Or is it one of those "both extremes are bad" thing?

This article[1], paragraph 2:

    Even as many doctors subscribe to the myth that eating
    fat and cholesterol leads to gallstones, research 
    indicates that eating too little fat and too many 
    carbohydrates in the form of grains, sugars and 
    starches actually leads to gallbladder ailments. ...

Or on WebMD from over a decade ago [2] .. as to the saturated fats... generally animal sources of fats are about half or less saturated, and generally a good mix.

[1] https://www.atkins.com/how-it-works/library/articles/dealing...

[2] https://www.webmd.com/digestive-disorders/news/20041004/more...

“Both extremes are bad” applies to everything, by definition of it being extreme.

Fair, though usually "drinking zero water" as an extreme does not cause death by water intoxication, and avoiding all alcohol does not usually cause liver issues.

So im curious how this particular extreme affects the galbladder.

See effects of too much potassium vs too little, or magnesium, sodium, phosphorous. The symptoms overlap because when the balance is off, it can have similar effects.