Forget any worries about gene modification and industrial farming - the real trouble with the food we eat began long, long ago. A growing number of scientists argue that we took a dietary wrong turn with the advent of agriculture some 10,000 years ago.
For them, the most nourishing diet is that of our hunter-gatherer ancestors - heavy on fruits and vegetables, supplemented by fish, lean meat and nuts.
"Cereal grains are what allowed us to leave the hunter-gatherer niche and form this vast cultural, technological society that we live in yet there are many problems with cereal grains," said Dr Loren Cordain, a professor at Colorado State University and a leading scholar of evolutionary nutrition.
For proponents of the Palaeolithic diet, the chief pitfalls of the modern diet are its reliance on grains and some processed fats that are ill-suited to a genetic make-up little changed in thousands of years and the cause of modern illnesses.
"Eventually you are going to find out that through proper diet and physical activity, you may delay the appearance of chronic illnesses or prevent them altogether," said Dr Artemis Simopoulos, an expert in essential fatty acids and genetics.
"Most mainstream nutritionists are going to say there's nothing wrong with fish and lean meat nor is there anything wrong with fruits and vegetables . . . We're saying two basic mainstream things," Dr Cordain said.
"The only thing controversial thing about this is we're saying don't eat grains and beans or dairy products." So, banish toast with jelly or Danishes from breakfast and turn instead to lean meat and fruit.
"Breakfast needs to move away from bagels, doughnuts, cereals and hi-carbohydrates," said Dr C. Leigh Broadhurst, a research chemist and nutrition expert at the US Department of Agriculture.
Palaeolithic peoples flourished from the first manufacture of stone tools some 100,000 years ago to shortly before the advent of agriculture. Blessed with foods of a veritable Garden of Eden, they grew tall and bigboned.
The advent of agriculture brought about a nutritional revolution - converting us into the only primates who routinely eat grains. Cereals now provide some 40 to 90 percent of human food energy whereas meat used to provide 20 to 80 percent.
The agricultural age also ushered in alcoholic beverages, commercial salt and sugar production. With industrialisation, we have widespread processing of food all to our dietary detriment.
Palaeolithic diet pioneer Dr S. Boyd Eaton points in his research to a fall of 11 percent in human cranial capacity now from its peak as consumption of animal foods has dropped.
In a milestone 1980s article, Dr Eaton says that of the four food groups recommended today - meat and fish, vegetables and fruit, milk and milk products and bread and cereals - early man got his nutrition almost exclusively from the first two groups.