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When people ask me about this, I like to start off by telling them that of the three macronutrients, carbs, protein and fat, only carbs are non-essential. We literally can't live without fat and protein, but we would do just fine with out carbs.

Most people don't know that carbs are not required to live. We've been sold a bill of goods on carbs and it's been hurting us for 2 decades.

And further, there are certain people who should be no where near carbs.

* Diabetics and pre-diabetics

* cancer patients

* the obese

* people who don't workout

Carbs aren't evil, they should just be used strategically. Namely, to gain weight. Bodybuilders and powerlifters have known this forever. To gain weight, eat everything but mostly carbs. To lose weight, keep protein high, fill the rest of your calories with fat and limit the carbs.

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This applies to type II diabetics, but not to type I. As a type I diabetic, I would be dead pretty quick without carbs. Proteins and fats can raise blood sugar, but they do it very slowly, so I would have no way to correct low blood sugars before they got out of control.

Minor nitpick, I know, but the two types get conflated often, leading to misinformation. I cannot count how many times people have been surprised that I am diabetic, since I am thin (which is normal, since it is not weight related, and actually leads to weight loss when untreated).

You are correct, diabetes type I should NEVER go on the LCHF diet - it's impossible.

I went on the LCHF diet in March, and have gotten rid of my type II completely - i also lost 10KG of overweight in about a months time.

Type II here, my endo-doc has me eat a certain amount of carbs at every meal. She prefers that I eat carbs that take longer to process, like fruits and vegetables. I just finished half a baked apple.

https://en.wikipedia.org/wiki/Diabetic_diet#Carbohydrates

http://www.diabetes.org/food-and-fitness/food/planning-meals...

That is not a "nowhere near carbs" diet.

If you truly don't eat any carbs at all (something that is extremely hard to do) I am pretty sure you end up in ketosis. That's not exactly a healthy state of affairs despite the fact that you can live that way. Practically speaking, there are too many things your body needs that also require you to eat things with carbs: vitamin c, folate, etc...

Are you thinking of Ketoacidosis? Ketosis is fine for people to live in and intentionally induced via the keto diet in quite a few people. It does remain slightly controversial if we need ketosis for weight management via keto, but I've seen nothing saying ketosis is harmful.

> I've seen nothing saying ketosis is harmful.

Really?

During ketosis, the body forms substances known as ketones, which can cause organs to fail and result in gout, kidney stones, or kidney failure. Ketones can also dull a person's appetite, cause nausea and bad breath. Ketosis can be prevented by eating at least 100 grams of carbohydrates a day. [1]

Ketosis occurs when you don't have enough sugar (glucose) for energy, so your body breaks down stored fat, causing ketones to build up in your body. Side effects from ketosis can include nausea, headache, mental fatigue and bad breath. [2]

[1] http://www.webmd.com/diet/high-protein-low-carbohydrate-diet...

[2] http://www.mayoclinic.com/health/low-carb-diet/NU00279/NSECT...

According to the study made by SBU, it is very hard to get into a ketosis stage that is dangerous. You would really have to skip every nutrition and only eat fat - doing that is dangerous and not even recommended by LCHF diet. The amount of carbs you get from sallads are about 5% of a diet, this is the recommended amount that would keep you from going into a high-ketosis stage.

I understand that links to webmd or mayoclinic are considered proof, but really, I don't trust them as anything other than a point to start googling (and googling shows everyone refers to them, and never to any primary source).

I haven't eaten meat or taken B12 supplement in over 20 years. According to those sources (unless they've updated in the last two years), I should be dead. (Well, maybe I am, but that's beside the point :) )

They state with the same level of authority things that have been proved without shadow of a doubt, and things which have been accepted hypothesis in the medical community but were never proved.

Yes, ketosis (by definition) means your body forms ketones. Yes, initially it changes body and breath odor, usually for the worse, and sometimes (rarely) also causes nausea (but so does kimchy or chutney if you start eating it as a main food). I haven't found any serious studies, but anecdata suggests that all of these symptoms pass within a couple of weeks.

I'm not posting this as a disagreement to anything you've said, but if everyone on that list decided to drop carbs for protein/fat, there wouldn't be enough food for everyone.

That's to say, before we can really cut out carbs from our diets we'll need to re-examine where our current food production is heading. The past half-century of advances seems to mostly have gone towards producing the most carbs per acre, albeit those carbs are typically then inefficiently converted into fat/protein (livestock). Soy is pretty good for mass protein production. Not sure if it would really be up to the task of what corn puts out in caloric density.

When I was growing up it was advised to skip the bread, pasta and potatoes if your goal was to lose weight. Skip being interpreted to limit, not eliminate.

This all changed in the 80's when fat became the culprit behind heart disease. Thus began the high-fat, low-carb diet trend we're on now.

Now we have the Swedes telling us fat is good for us, actually reducing the risk of heart disease. Seems like my grandma was right all along: watch out for that bread and pasta.

"we would do just fine with out carbs" - Intuition leads me to want to disagree with this. How would the body handle not having ANY fiber? I'm curious. Fiber helps digestion, feeds the happy parts of your internal biome, makes your colon happy, etc. I can't imagine that eliminating all carbs is good for your body.

When you up the fat, things flow very well in the colon front. Particularly if that fat is MCT based (coconut, mct oil).

Normally if you follow a low-carb diet, you get your fiber from greens. I believe the statement was targeted more towards carbs like bread, pasta, rice, etc.

Indeed.

Ok, but that's not what you said? You say something bold and provocative and then start carving out exceptions buried downthread.

As I said elsewhere in this discussion: "I feel like all the simple answers in nutrition are BS and the only short answer is 'it's complex.'"

Ok, here it is. Technically, we don't need carbs. Whatever that means, it is what it is. Carbs are a non-essiential macronutrient.

We need some vitamins, minerals and what not as well as protein and fat. We don't need carbs. Some of those vitamins and minerals come from plants, which have, as we say in the biz, trace carbs and fiber.

When I'm cutting down for a photoshoot I go keto. I might not have a veggie for weeks. My bloods and panels all look fine. I mostly eat veggies b/c I feel bad for not eating them.

I do take a multivit every day and I'm eating plenty of fat which helps the colon move things along.

When I'm gaining muscle, I do eat carbs. Lots of carbs. But we don't need carbs.

> But we don't need carbs.

Do you have any science to back up this bold claim?

And what are you claiming carbohydrates are? Simplex and complex carbohydrates - sugars and starches?

It seems like you're saying that we don't need carbs, but that eating a diet with no carbs means we lose out on all those foods that have other useful nutrients (ie green vegetables). So, we tend to eat diets that have carbs to get the other benefits. Is that right?

Well this is an interesting result of marketing.

Fruits and vegetables offer fiber. For example, dark greens offer 6.4g of fiber per serving while whole grains offer 2.4g.

I'm not sure what you are trying to say here. Fruits and Vegetables are mostly carbs (except for the rare ones like avacados) just like whole grains. Presumably if you were to cut out all carbs they would be on the chopping block too.

Vegetables are mostly water. Lots of them provide more fiber than other carbs (and even more protein than digestible carbs). Pedantically you would have to cut them to eliminate carbs. On a practical basis, there isn't much reason to.

Seems to work okay for the Inuit

Life expectancy in aboriginal populations is hard to measure. Modern populations have many complex factors affecting life expectancy, including cheap alcohol.

http://www.statcan.gc.ca/daily-quotidien/080123/dq080123d-en...

http://www.reuters.com/article/2008/01/23/us-inuit-idUSN2362...

I dunno, that doesn't sound okay.

I understand the reasoning for 1, 3 and 4 but why cancer patients?

As far as I know this is still some preliminary research, but there is some evidence that chronic high blood sugar can cause cancer to grow more rapidly than a steady and lower level of blood sugar. The working theory seems to be that because the cancer is growing more rapidly, it requires more energy. By feeding it (literally) a steady supply of higher blood sugar levels, you are allowing it to grow faster than it would otherwise. I believe this is still all only working theory at the moment, though, and I wouldn't be surprised to see the whole idea in general get walked back at some point (even if it does sound plausible). It's fairly new stuff, on the time scale of cancer studies.

I can't find my original study link atm :/ some quick googling brought up this one, but it wasn't the study I was thinking about: http://www.sciencedaily.com/releases/2013/06/130605190158.ht...

basic theory goes like this: the body doesn't need carbs to live, but cancer cells do. You are starving the cancer by not ingesting carbs. It seems the cancer cells lack the ability to derive energy from ketones and fatty acids, which is where humans would get the energy on a low-carb diet.

> We literally can't live without fat

I don't think that's true of fat. Your body can synthesize the fat it needs from sugars. There is a bit of a debate about whether there are really "essential fatty acids" that people can't synthesize, but if they exist the quantities required are very small.

The human body cannot live without ingested fatty acids. These are called "essential fatty acids" and include linoleic and linolenic acids.

As I said, that's debated. People have experimentally gone long periods with zero fat intake without ill effect.

It's under debate in the same way that other well established scientific ideas are under debate.

That there are essential fatty acids for humans could certainly be disproven, but "going long periods with zero fat intake" is not sufficient evidence to disprove established biochemistry.

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