LMT appears to speak from a vegetarian/vegan position rather than a neutral fact based position - the use of 'in my opinion' reflects the position exactly.
Lee seeking justification from antelope eating ancestors has ignored the likelihood that a hunter gatherer also gathers and may well subsist on berries, fruit vegetables and honey, with antelope being a rare treat. Plus antelope, in my experience, is usually pretty low in fat (as is tuna!)
Obviously, in the developed west we are able to easily eat far too much of everything and do far too little. Plus we are drawn to do this by ever more tempting treats and a self indulgent culture, encouraged, if not propagated, by the advertising industry. It may even be necessary for our economic model...
I am still waiting for a really solid, well peer reviewed and conclusive set of studies on optimal diet for what ever purpose. I can quite believe that it won't reflect what our ancestors ate, any more than it might entirely plant based. I am pretty confident that it won't include a lot of sugar or alcohol;)
There are many studies and a near complete scientific consensus on a optimal diet. It's the 'eat-your-greens-and-do-some-exercise' one I mentioned earlier. Of course, there's no money or hype in common sense.
Humans never ate much meat, until the debut of the supermarket it was difficult to obtain (given its tendency to run away). As such, we are not especially good at handling large amounts of dietary protein, unlike obligate carnivores who not only can digest large amounts of animal protein, but have a lifestyle suited to the calorific requirements of chasing and catching that protein. We're wide-spectrum omnivores, and as such most humans since the dawn of time have likely received the majority of their calories from carbohydrates. Human civilisation is a corollary for our being able to farm and produce sufficient carbohydrate without the limits of our peripatetic gathering lifestyle.
Modern life, of course, brings with it (for those of us in the developed world at least) a surfeit of easily absorbed calories and often a sedentary existence. Dietary revisionism is non-sensical, we eat too much and do too little. Demonising food groups (fat, carbohydrate etc.) might be appealing, but again, it doesn't make a lot of scientific sense. It's an inviting reductionism.
Its also often said we've evolved to do this and that. We don't evolve to do anything. We didn't evolve to eat meat or carbohydrate. Evolution isn't active or directional. If anything, humans have been successful because of their dietary flexibility – we don't have to survive solely on meat, or bamboo. We can generally do a reasonable job in digesting whatever is available.