lifesnotfair:

That's a lot of questions, but I'll do my best!

Re: Art Devany.  When I wrote ELAP his blog was private, accessible by paid subscription only.  It's come and gone several times over the years...the upshot is that it wasn't a direct influence on me, since it wasn't available to me while I was formulating my own dietary philosophy.

Re: carbs and tubers, I think the original Perfect Health Diet recommendation of 15-20% carb "calories" is a good starting point for most people, because it's probably close to an average mostly-sedentary human's need for carbs.  Some people require fewer carbs in order to maintain weight loss: post-menopausal women and the formerly obese seem to have this problem frequently.  Some people find they seem to do fine on higher-carb diets as long as they're otherwise paleo: usually healthy, moderately active males with no history of obesity (20-30 extra pounds doesn't count).  And one's capacity to store glucose goes up with one's degree of intense, glycolytic physical activity...the more activities you do that leave you out of breath and your muscles shot, the more glucose you'll want in your diet.

Re: weight loss stalls, the evidence seems clear to me that obesity is multifactorial.  Metabolism is complicated, diets vary dramatically, and it's empirically clear that the same weight loss strategies don't work for everyone...so the idea that everyone accumulates fat for the same reasons seems unlikely to me.  I see weight loss stalls as an indication that whatever your biggest problem was, your current approach fixed it...so now, you've exposed another problem that was previously hidden by your first, bigger problem!  (Or, perhaps, was caused by your solution...for instance, vegans tend to feel great for a while due to eliminating so much processed junk food, but eventually the nutritional deficiencies catch up with them and they start feeling even worse.)

With the case of LC/VLC, it works very well for most people...people generally find it easy to strip a bunch of weight.  Does it get them all the way to a six-pack, or their goal weight?  Often, no...but I have to ask another question here, which is "Would you have hit a similar weight loss stall, complete with low energy, after losing 50-100 pounds on any diet?"  Given what we know about things like leptin, the answer seems to be "It's likely."  So I'm reluctant to blame every stall on a failure of LC/VLC...and there are plenty of reports of failed experiments with "safe starches" that resulted in fat gain.

That being said, given a multifactorial explanation, it seems likely that the people who stall on VLC and overcome it by adding starches have regained their ability to oxidize fat by going VLC, and later found that something else becomes their biggest problem and VLC won't cure it.  However, would they have even got to that point without fixing their biggest issue (impaired fat oxidation) with VLC?  I'm not sure.

Yes, I'm rambling a bit...but these are complicated issues you've raised!

Moving on: the problem with carbohydrate consumption is that our ability to store carbohydrate is limited (muscle and liver glycogen), and the preferred alternative disposal pathways for excess carbohydrate (metabolic flexibility leading to whole-body carbohydate oxidation, increased thermogenesis, etc.) only seem to work well in healthy people.  So Kurt Harris, being healthy, can eat almost all the carbohydrate he wants to...but there is plenty of empirical evidence that most obese people, who usually exist in a state of metabolic dysfunction, do much better by starting with low-carb diets.  Some of them can start consuming carbs again, and even do well by it...but some can't, and find they gain weight with carbs no matter what.  So I don't put much stock in that particular religious conversion, based as it is on the n=1 of a healthy person who was never obese, and who fixed any fat oxidation problems he may have had with years of VLC.  (See this article: Anti-Nutritionism, L-Canavanine, And The Limitations of N=1 Self-Experimentation)  

As for myself, I eat potatoes, and occasionally white rice, because I do a lot of intense physical activity, and because I'm healthy and metabolically functional.  But unlike many in the community, I don't feel the need to tell the low-carbers they're necessarily Doing It Wrong, because I don't see the evidence that low-carb diets are necessarily harmful.  Sure, there are unhealthy low-carb diets...but there are plenty of unhealthy high-carb diets, and some people find low-carb to be a necessary patch on a broken metabolism.

And I would be cautious about attributing 15-20% of "calories" to fruit and veggies unless you eat a lot of bananas or make smoothies...do an inventory sometime and see what you're actually eating.  Furthermore, as I implied in my latest article about "calories", the energy in plants, particularly leafy greens, may or may not be available to you in the same way starch or sugar is.

JS

lifesnotfair:

I don't have an answer to the general case of food combining, but I have a few observations:

1. Our digestive systems are smart: ingesting meat causes the stomach to secrete more acid to help break it down, and bile to help digest the fat.  This actually increases the digestibility of any food you eat along with meat!

2. Many of the vitamins in vegetables are fat-soluble, and therefore are only absorbed in significant quantity if we eat them along with a source of fat, e.g. fatty meat.

3. Insulin is not selective: there's no such thing as "protein insulin" or "fat insulin".  Therefore, eating carbs+fat at the same time will cause the fat to be stored along with the carbs, because even though it's OK for fat to hang around in the bloodstream for a while, high blood sugar is toxic and the body needs to get it stored. 

Empirically, we see that weight-class athletes, bodybuilders, and others whose success depends on cutting that last few percent of fat follow either a very low-carb diet or a very low-fat diet, with nothing in between.  (Though they sometimes alternate, e.g. leangains and the variants of CKD.)  So while it doesn't matter so much for the general health case, if you're trying to get "ripped", "shredded", or whatever other violent term you use, it seems best to stay out of the muddy middle.

So from what I can tell, most of the traditional rules are unsupported by science, and there are good reasons to combine meats and veggies.  Starch and fat, however, might be somewhat mutually exclusive if you're going for extreme leanness.  However, I'm open to a deeper exploration of the science here.

JS

lifesnotfair:

If you want to never become muscular, always avoid the combination of protein and starch!  Insulin is required to stuff protein into muscles.

Remember in the 1990s, when bodybuilders went from "huge" to "bizarre-freaky-alien-huge"?  Steroids have been around forever...that's when they discovered how to use injectable insulin to force mass gains.

Also, the idea that an acidic stomach somehow inhibits the digestion of starch is...how can I say this...bunk.  Starch is digested in the mouth, which is close to neutral pH, and in the small intestine, where the acidic pH of the stomach has been neutralized by bile.  (The pH in the ileum is 7-8.)  And since the optimum pH for amylase is about 6.5-7, it doesn't matter if your stomach is pH 1.5 or pH 3...you're still not going to get significant amylase activity there.

There's a reason those raw-food anti-combining gurus tend to look skinny, sickly, and have no muscle tone...they're peddling woo, not science.

JS

lifesnotfair:

Eating meat will make the stomach more acid: this has been established since at least the 1930s.  Thus, anything you eat with meat will be digested more completely.  Perhaps a huge bolus of starch with no meat isn't being completely digested?

I found this food combining table, which automates the choices available on the Gracie Diet.

Ironclad rules:

* Starches do not combine with each other.

* Raw or cooked egg yolk, coconut water, brewer’s yeast, coffee, and several kinds of tea are considered neutral and compatible with any food.

* Space your meals at least 4.5 hours apart.  No snacks!

* Avoid: Sweets, canned foods in syrup, pepper, clover, cinnamon, pickles and vinegar.

* Never eat pork in any form.

The main diet combining rule seems to involve never eating meat and fruit together...though meat with veggies and starch is fine, and fruit with starch is fine.

My take: an interesting combination of smart ideas and woo.

JS