So long as it's grass fed it should be fine.

http://www.eatwild.com/foodsafety.html

Yeah, make sure that it is high quality. Otherwise you will get horrible consequences. I experienced headaches, tiredness and even sore muscles / muscle hardenings.

The thing is, I cannot gain weight. I just cannot. Some have told me to eat more fat, yet still cannot gain weight. Interestingly, only carbs make me gain weight

If you are very very lean and just can't gain weight you maybe have a hormonal issue. One simple way (at least in theory) to fix that is using cold thermogenesis. Read Jack Kruse blog about this topic. It's hard to put this stuff into practice (e.g. who wants to stay in a tub for 30 minutes at 8 degree celsius?).

I was just curious about different claims of Jack Kruse so I gave it a try. And (by coincidence) I gained (much) weight within some weeks.

This is all nonsense. Palaeo studies have shown that early humans had very thick bones which corresponds to having very strong muscles, so that they were found to be stronger than modern athletes.

Heard of that several times. Do you have a link to an internet site providing a more in-depth view?

I don't think early humans (even the hunter-gatherers) were huge muscular men. They were probably under-weight but lean.

Oh, this will be a funny discussion! 

First of all: what is your goal by this discussion?

Then, please clarify: what is an 'early human' for you? Homo habilis? Homo erectus? Homo neanderthalensis?
What are huge muscular men? Definied by relationship of fat and muscle?
How do you define under-weight?

Anti-Nutrients in vegetables?

Aren't anti-nutrients a problem of grains, beans, legumes and potatoes. I don't thinc that e.g. a fennel (as long as its taste is pleasant) is harmful?!

One thing I would consider as a trigger for pimples: overeating fruits / sugar. Maybe not the fruits are your real problem but the amount of fruits.

Anaerobic Activity can be sustained on a zero carb approach if the diet is well formulated. After 3-4 weeks of keto-adaption there shouldn't be any difference in athletic performance; other than being able to exercise longer

How do you define 'well formulated'? And did you try it at yourself?

You can google this query and come up with lots of options. But I want to add this warning, in case you find some and want to buy a lot to minimize postage costs, check your quality first.  I gave up on raw macadamia nuts because they always tasted stale. Hawaii, Australia and Africa were the main sources. I can't say the reason for sure, but my taste buds told me that the nuts had been hanging around in a warehouse for too long. You might find some with a current-year harvest date included.

If you have 1st-class quality macadamias (not heated; ...) and it tastes stale then your body has no need for them (at the very moment). Give 'em another try some hours / days later.

I sleep 7-8 hours.

Go to sleep at 10 PM (in winter at 9 PM) and wake up around 6 AM.

I love my sleep.. I get so sweetly sleepy in the evening.. and wake up refreshed without any alarm. New to me, I never was like this before I started to follow the Kruse protocols. They really fixed my circadian biology!

I can confirm that. In winter i go to bed around 10pm. In summer it's between 10 and 11pm. In the morning i wake up between 5 and 6am. I feel very refreshed then and I don't need an alarm clock any more 

Just to mention: my sleep quality depends heavily on my foodstuff and the way of eating. Dinner around 6-7pm, carbs (if any) at lunch but not at dinner, minimizing artifical light after sunset.

For Instincto to work and be a healthy diet it would have to base on what grows in the season where you live.
ONLY that way I can agree it might a great theory. Any other way is just an illusion and a lie. Sorry to be harsh but it is a biologic fact we can only consume carbs when we get plenty of sunlight on our skin, without getting hurt in one way or another. The sicker we are the more it will hurt to live in such a mismatch.
There is a reason why fruit grows only in seasons or places with lots of sun and not too cold.

There is a reason to that.

Everything in nature happends for a reason.

As long as Instincto do not see this fact, the theory is flawed to me.

Inger, eating in season is favorable. I agree with that. But as long as you are suffering of diseases one should eat foodstuff that helps your body rebuilding/healing most. Apparently there is a heavy bias towards exotic (tropical) fruits in such conditions. Maybe we are most adapted to these fruits?

True. I have differing views on health and nutrition, and I'm glad we can all talk about our varying beliefs here and what works for us.

I'm trying to recover (though recover might be the wrong word, as no one can tell I'm schizophrenic unless they look at my medical records) from a debilitating illness. Since I became sick through rather unnatural means. I feel I might have to take a side track (however long it might take) before I can just eat raw, unprocessed foods and obtain optimal health. Animals in the wild are typically pretty healthy being their parents ate raw, they grew up raw. If the situation were the same with me I probably wouldn't want to take supplements, eat specially fermented foods, etc.

However I do think there's something to instincto. Iguana has pulled it off for a long time, and seems like he's doing great.

In the short term you can improve your health by many types of diet. Take a step back and review: what do these diets have in common? No flour, no (processed) sugar and no processed foods in general. But the difference can be seen in the long term. Can you recover from all your sufferings? Will your foodstuff be a pleasure or are you leaving your plate on the lookout for another foodstuff?

Just my 2 cents (without diving too deep into this issue).

Now let's get back to the topic!

Fermented plant foods... Lol like home made fermented pickles, my new favorite. I use this recipe.

I just wanted to make sure what kind of fermentation you were thinking about. As long as we are in the scope of 'instinctive eating' there is no fermenting by adding salt (or any other artificial stuff). There is only fermenting by 'time' (e.g. mold).

I mainly eat fruits. Not necessarily because I think vegetables digest poorly, but because I eat the plant foods for their carbs and most veggies are low carb.

Yeah, most veggies are low carb. Except dried figs and dates Maybe even durian and mango contain much more carbs than a 'standard' fruit. At least it feels extremly sweet on my tongue.