Paleo diet founder Loren Cordain​ didn't race to pop the pasta on the boil after reading the paper, titled The Importance of Dietary Carbohydrate in Human Evolution.

"It is always best to let the data speak for itself and not let poorly tested and poorly thought out hypotheses by charismatic individuals guide the scientific method," he said, slamming the study, co-authored by researchers from the University of Sydney.

"The primary hypothesis of the paper is that concentrated starch from plant foods represented a powerful selective responsible for the evolutionary increase in brain size in humans," Cordain said.

But, he argues, their hypothesis has a heap of prehistoric holes.

"First starch is largely indigestible in its raw state without cooking," Cordain continues.

"The first evidence of the control of fire appears in Europe about 300,000 years ago, whereas the available evidence suggests that the ability to make fire at will did not occur until about 75,000 to 100,000 years ago.

"However, the process called encephalisation which increases brain volume began by at least 2 million years ago – long before the advent of the ability to make fire at will. Hence concentrated starch sources could not have represented an evolutionary stimulus for encephalisation."

Paleo poster girl Nora Gedgaudas, author of Primal Body, Primal Mind, also roasts the "potato heads" and "grain brains".

In a lengthy post addressing the importance of carbohydrate paper, Gedgaudas accuses "aggressive government-controlling transnational Big Agribusiness interests, large multinational chemical industries (marketing fertilisers, pesticides and herbicides, etc.) and corporate food industry efforts," for a modern day diet high in sugar and starch-based carbohydrate foods.

"If starch in any form were so healthy for the human brain, then certainly more would be better and the human brain today – given the uniquely starch-based diet of our times – would be even larger – growing by leaps and bounds and better than ever," Gedgaudas adds. "But the opposite is actually true.

"We humans have literally lost just over 10 per cent of our brain volume over the last 10,000 years since the development of agriculture, where cheap and easy to produce starch became a much more prevalent part of the human diet.

"Since the advent of agriculture, however, we literally shifted from a diet comprised of close to 90 per cent animal source foods rich in brain-building fats to as little as 10 per cent, in favour of starch."

The bottom line, she concludes, is this: "We were exquisitely forged by Nature as Paleolithic hunter-gatherers to be primarily 'fat heads' and not 'potato heads' or 'grain brains.' "

Do they have a point?

Perhaps the Paleos and the potato heads both have points, but the optimal diet debate has degenerated into a slanging match of cherry-picked papers and meat versus carbs and fussy one-size-fits-all macronutrient breakdowns.

"There comes to be some disagreement as to when cooking began," says dietitian Dr Joanna McMillan.

"I have read reports stating as far back as 1.8 million years ago – well in line with the paper's hypothesis of the importance of starch. I would note that Loren Cordain champions his own research line as much as others do – but that his own paper I quoted you before stated that a true Paleo diet was more moderate in carbohydrate – akin to a Med diet, not a low-carb one.

"This is not meat against plants," McMillan adds. "We are clearly omnivorous for millennia. But our guts also adapted to a diet that includes cooked food. This made is easier for us to digest and obtain nutrients, hence the gut shortened. Our jaws have also become smaller – compare us to a chimp or other ape."

In the extreme response to find an answer to the obesity epidemic and increase of chronic health conditions, the diet debate appears to have lost perspective and balance.

"I agree entirely that the omega-3 fats are crucial for brain health and the role of seafood in delivering these to us is well documented," McMillan says. "So as usual the arguments come down to a balance of foods."

Dietitian Susie Burrell agrees.

"We could indefinitely spend countless hours debating various scientific papers and what they mean but the truth is it had little practical relevance when more that 60 per cent of Australian adults have significant weight issues whether it is from too much carbohydrate, too much fat or just too many calories.

"As a general rule of thumb our carbohydrate intake in particular refined carb intake has been too high, especially given massive reductions in physical activity."

Choose the diet, macronutrient ratio that works for you. But remember that there are vastly different perspectives on what the bottom line is or ought to be. For most of us, going nuts over meat versus starch versus sugar versus gluten versus whatever else, is a moot point.

For the only one-size-fits-all is that more plants in our diets is positive and the less crap and refined carbs the better.

This is one thing that the fat heads, potato heads and grain brains all agree on.