Valencia:

Thank you!  For a comprehensive program that will help you improve your health in many more ways, read my guide "Eat Like A Predator, Not Like Prey."

JS

Nina:

Even at 13% bodyfat (which is very low for a woman) you've still got well over 50,000 "calories" worth of fat reserves.

I'm in a similar situation: it's nearly impossible for me to gain weight unless I let myself drink a lot of soda and eat lots of bready junk food, and even then I don't gain much. 

The biggest advantage for me of breaking my sugar addiction has been that I used to have to eat every three hours or I became cranky and irritable.  Now I usually eat only 1-2 meals per day...it's wonderful not being forced to interrupt what I'm doing to find food every few hours.

So yes, you can safely break your sugar addiction so long as you're eating enough other food to keep your body happy.  If you find yourself losing too much weight, eat more...and if that doesn't work, start drinking half and half (heavy cream, if you're lactose intolerant) or eating more potatoes and rice.  My general eating strategy, by which I've enabled myself and many others to shake their sugar addiction, is here: Eat Like A Predator.

JS

DODAH:

Your sources, whatever they are, are factually incorrect.

1. Paleolithic people, in all cases for which we have evidence, had longer lifespans than the agriculturalists who followed them.

2. Their teeth and bones were far more robust, and show no evidence of chronic malnutrition -- unlike agriculturalists, whose remains show extensive dental caries (cavities), porotic hyperostosis (from iron-deficiency anemia, i.e. not enough meat), etc.

More information here: Indian Knoll vs. Hardin Village

"Why not base it on the millions of years of evolution of apes and that would show that diet should be 100% sugar based."

If you're happy being a 60-pound proto-chimpanzee that is limited to living in equatorial forests, and has a tiny 300cc brain incapable of making even the most basic stone tools, go right ahead!  The rest of us left that behind about six million years ago -- in favor of an existence requiring both more brainpower and enough meat to support it.  See my series-in-progress "Big Brains Require An Explanation".

"Eat everything in moderation, at a calorie maintenance level, regular exercise, lots of water. Its really not hard."

If that were true, we wouldn't have an obesity epidemic!  

JS

nancy:

"Gluten-free bread" can contain any number of ingredients, as there's no universally accepted way to make it.  (Typical contents include potato starch, rice flour, tapioca starch, sorghum flour, bean flour, cornstarch, ...)

However, it's all just processed carbohydrate -- and while gluten is unhealthy for several other reasons, the usual effect of simply substituting gluten-free junk for the junk you used to eat is a diminution of your savings account.  (Gluten-free bread and cracker substitutes are expensive!)  It's best to substitute the bready junk you used to eat with real food -- meat, fish, eggs, vegetables (including root vegetables), some nuts and fruits.  Eat like a predator, not like prey.  

That being said, gluten-free junk is less bad for us than gluten-based junk, and I do indulge in an occasional treat...but it's still processed "carbohydrate" (sugar).

JS

kazy:

Blood sugar spikes and crashes are only one contributor to hunger and weight gain: nutrition is a primary driver, as I've shown in my presentation "Why Are We Hungry?"  (Print articles here.)  So while slathering butter on a croissant does blunt the blood sugar spike (and adds at least a little bit of fat-soluble nutrition), substituting the white flour-based croissant with food that isn't just empty calories will keep you less hungry and produce better results.

To that end, sprouted bread will indeed be superior to other breads, but even the humble potato will provide superior nutrition -- and whole eggs, meat, and vegetables will be even better still. 

I agree that dark chocolate in moderation isn't a bad thing: the darker it is, the less sugar it contains vs. cocoa butter, antioxidants, and the odd stimulant and euphoric.  My current favorite is the Lindt 90%.

"But that has more to do with the cheaper processed foods in this country that is available to them. Not something they would eat living in Africa."

I agree.  Indigenous populations, whether Native American, Australian Aboriginal, or Pacific Islander, suffer much more from obesity, diabetes, and other "diseases of civilization" upon adopting a diet of processed industrial Western food than Westerners do -- whether they adopt the processed industrial diet in their homeland or upon moving to the West. 

JS

Skgr:

I don't content that a high-carb diet always causes metabolic inflexibility -- that's clearly not the case, and a combination of other factors Including genetic susceptibility) must also occur.

Also, I would be careful about generalizing your and your family's experience to the rest of the world: I've received many communications from people who find carbohydrate of any type addictive, regardless of taste.

Finally, our guts are NOT more like an herbivore's than a carnivore's: our stomach acid is just as strong as a carnivore's, and our digestive tract is NOT "much longer than a carnivore's." (Further discussion, including links to scientific literature, here.) Nor do we have a rumen or a cecum, necessary to extract significant energy from vegetation (the rumen and cecum are places where bacteria ferment vegetation into SCFAs.) And we don't need huge teeth, as we've been using sharp rocks for over 3 million years.

JS

Skgr:

I've been very busy this summer, primarily with my 2014 AHS presentation, and am just now catching up with all the unanswered comments -- including yours.

"Do you believe that humans are primarily carnivorous (about 75% animal based foods and 25% plant based) or omnivores that eat about equal amounts of animal and plant materials. (Please note, I'm not asking this based off of mass but off of caloric energy)."

Humans, as we collectively exist today, can survive off of a wide range of diets. That being said, I believe the optimal diet generally involves a higher percentage of calories from animal sources (including fish and shellfish) than from plant sources -- and that the plant-source calories should be from plants (e.g. vegetables and tubers) and not acellular carbohydrates (e.g. grains and sugars).

I contend this from several angles:
1. It's the most parsimonious interpretation of the archaeological evidence
2. The nutrient density of animal foods is far higher
3. Our digestive and metabolic systems are not great at interconverting nutrients, unlike those of an herbivore (which ferments cellulose to SCFAs) or a pure carnivore (which is much better at gluconeogenesis)
4. Humans are incompletely adapted to high-starch diets (see below)
5. 40 years of low-fat dietary recommendations, and the shift from animal to seed-sourced fats, has made America fatter than ever

"Doesn't our saliva contain amylase, an enzyme that breaks down amylose (a complex carbohydrate)?"

Yes, it does. So does the chimpanzee, which is primarily frugivorous and thus has little use for salivary amylase: thus it only has one copy of the AMY1 gene. Most interestingly, the amount of amylase humans produce varies dramatically between different people:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2377015/
"individuals from populations with high-starch diets have on average more AMY1 copies than those with traditionally low-starch diets."

J Nutr. 2012 May;142(5):853-8. doi: 10.3945/jn.111.156984. Epub 2012 Apr 4.
High endogenous salivary amylase activity is associated with improved glycemic homeostasis following starch ingestion in adults.
Mandel AL1, Breslin PA.
http://www.ncbi.nlm.nih.gov/pubmed/22492122
"HA individuals had significantly more AMY1 gene copies within their genomes than did the LA individuals. We found that following starch ingestion, HA individuals had significantly lower postprandial blood glucose concentrations at 45, 60, and 75 min, as well as significantly lower AUC and peak blood glucose concentrations than the LA individuals. [...] These observations are interpreted to suggest that HA individuals may be better adapted to ingest starches, whereas LA individuals may be at greater risk for insulin resistance and diabetes if chronically ingesting starch-rich diets."

Nat Genet. 2014 May;46(5):492-7. doi: 10.1038/ng.2939. Epub 2014 Mar 30.
Low copy number of the salivary amylase gene predisposes to obesity.
Falchi M et.al.
http://www.nature.com/ng/journal/v46/n5/abs/ng.2939.html
"The OR value of 1.19 per copy of AMY1 translates into about an eightfold difference in risk of obesity between subjects in the top (copy number > 9) and bottom (copy number < 4) 10% of the copy number distribution."

In other words, the process of human adaptation to a high-starch diet is incomplete, suggesting it 1. took place very recently and 2. is still in progress. Do you know how many AMY1 gene copies you have? Why take the risk?

Re: GI tract length, you're not comparing apples to apples. If you only count the human torso as "body length", you must also only count the equine torso as "body length". This means you can't count the head and neck, and the average horse is no longer 8-10 feet long! The average horse's back is 1/3 body length, so add a bit for the part of the croup behind the peak, and we'll call it slightly over half body length. (Stretch out a horse's neck and head...they're quite long!) Result: horse intestine = 18-22x torso length.

In contrast, the average human torso is about two feet long, for about 10x-14x torso length...so the human's still substantially shorter in comparison. (I didn't see that the upper-bound 30 foot figure I linked previously includes the esophagus and stomach, so the intestine is perhaps 28 feet. The lower-bound figure of 20 feet doesn't change.)

However, I find the comparison between us and our closest primate relatives is far more relevant. Humans have a smaller gut in proportion to body size, and much more of it is dedicated to the small intestine. For instance, a (folivorous) gorilla's colon comprises over half of its gut, as does a (mostly frugivorous, with occasional meat) chimpanzee's. In contrast, our own colon only occupies 17% of our gut, strongly suggesting a greatly reduced intake of plant foods.
(Ref: Milton 2003, p. 99. http://books.google.com/books?id=xHYxSHr86T8C&lpg=PA93&lr&pg=PA99#v=onepage&q&f=false)

Yes, humans can usually survive on what's available: people regularly grow to adulthood on a diet of McNuggets, takeout pizza, and gas station burritos! Furhtermore, the ability to survive periods of low prey availability would have no doubt been strongly selected for, which is why we're omnivores, not pure carnivores. However, I'm concerned with what's optimal for health, not just what allows us to survive...and the evidence points me towards a primarily animal-based diet. (By calories, though perhaps not by weight depending on the source.)

JS