I actually think that IS true... too much protein (and fat) can lead to obesity.
What I've been discovering from the research I've been doing is that the problem isn't excessive protein (and fat) by themselves, it's protein and fat in the presence of too many carbohydrates. Most of the studies that malign fat and protein never document or even address how much carb their study participants were eating.
Here's a crude example to try and illustrate the idea:
Fire can destroy, and it can also be of benefit. The pilot light on a furnace is there so that the furnace can operate properly and keep the occupants warm. Hearing that "the pilot light is on" shouldn't be alarming in and of itself. However, given the information that the house is being fumigated under a tent (the gases are flammable), the information that the pilot light is on would be horrifying!
Fire by itself isn't harmful or helpful. Fire in the presence of large quantities of flammable gas is an extremely dangerous situation. Fire in the presence of the right components (small gas supply, in a contained way) can be very beneficial.
Similarly, protein (and fat) by themselves aren't harmful or helpful. Lots of protein--in the presence of large quantities of carbohydrate--correlates to very high risk of diabetes, heart disease, hypertension, and obesity. The part that gets missed is that lots of protein--in the presence of limited quantities of carboydrate--is beneficial... promoting muscle growth, for one.
I hope I'm not simply being argumentative. My passion on this subject comes from the information I've piled into my head over the years. (I'm sort of a science & information vacuum.)
My father is very obese, his total cholesterol / HDL is 5.1 (at risk for the disease cluster mentioned above). The only time he ever lost weight was on a restricted carbohydrate diet. Sadly, he doesn't subscribe to the saying, "Nothing tastes as good as thin feels."
FWIW, I've been reading up, getting a better understanding of the issues surrounding high levels of ketones in the blood and whether this risks kidney damage. I'll report back when I've done a bit more research.
--- added 3/21/02 ---
First, a correction of a previous post. Switching to a low carb diet can double one's protein intake or more. I was wrong!
Second, some information. Blood ketone levels are monitored and controlled by the body just like it regulates blood glucose and pH levels. A healthy person will suffer not in the slightest from ketones in the blood. (Alcoholics, uncontrolled diabetics, and people on prolonged fasts may have ketones beyond the normal range.) It is highly unlikely that anyone besides insulin-dependent diabetics will build up large amounts of ketones.
Source: Is Ketosis Dangerous?
(I know it's from the website run by the devil himself but he lists references! I see a lot of unsupported assertions in various pages on the web, and the ones with references to scholarly works and specific studies always seem to be the most accurate.)
