Scots have been eating porridge for 5,500 years, according to new research which traced the national dish back to Stone Age settlers in the Outer Hebrides.
Primitive farmers kept themselves fit and healthy by eating a gruel consisting of warmed milk - and wheat.
It puts the energy boosting meal's origins back by about 3,000 years, say British scientists.
Lead author Dr Simon Hammann, of the University of Bristol, said: "Our results represent the first direct evidence for the cooking of cereals in Neolithic pots from the 4th millennium BCE."
Occasionally dairy products were also mixed with meat - to create an early form of stew.
The discovery is based on chemical analyses of residues on "incredibly well preserved" pottery fragments.
They were unearthed in waters surrounding ancient 'crannogs' - artificial islands on which shelters were erected on lochs.
Dr Hammann said: "They indicate Neolithic communities in the region may have been consuming wheat between 3600 and 3300 BCE.
"Wheat may have been cooked with dairy products to produce a milk-based gruel or porridge."
People visiting the crannogs used smaller pots to cook cereals with milk - and larger ones for meat-based dishes.
Co author Dr Lucy Cramp, also from Bristol, said: "This research gives us a window into the culinary traditions of early farmers living at the northwestern edge of Europe, whose lifeways are little understood.
"It gives us the first glimpse of the sorts of practices that were associated with these enigmatic islet locations."
Porridge oats come from a grain called Avena sativa - a relative of wheat within the grass family.
Farming first emerged in Britain and Ireland around 4000 BCE. Pottery was also being introduced.
Plant remains show cereals were being consumed as agriculture replaced hunter gatherer lifestyles.
There may have been regional variations in their importance within different culinary traditions - but finding traces of growing cereals to eat has been challenging.
Scanning techniques have now identified traces of lipids, or fats, from dozens of ceramic vessels from four sites on the Isle of Lewis off the north west coast.
Many were intact and decorated - suggesting they may also have had some sort of ceremonial purpose.
Cereal 'biomarkers' were detected in a third - providing the earliest evidence of human consumption of grains in this region.
They were "strongly associated" with residues from dairy fats - suggesting they were cooked together as a milk-based porridge. Wheat may also have been boiled in the stew.
The traditional Hebridean ridged and non ridged baggy jars were collected during recent underwater surveys and excavations.
There were also pieces of 'Unstan' type bowls - shallow containers with grooved patterning - and shouldered designs where the rim is folded over for gripping.
Dr Hamman said: "Gas chromatography and high resolution mass spectrometry were then used to analyse organic residues from these pottery remains.
"We detected molecular biomarkers for cereals, indicating wheat, and other foods that were cooked in the vessels.
"It shows wheat may have been more present in Neolithic diets in this region than previously thought.
"It may have been prepared with dairy products, perhaps as a type of milk-based gruel or porridge."
What is more, a strong link was identified between the size of the pottery and its use, with smaller-mouthed vessels associated with dairy products.
Dr Hammann said: "Wheat may have played a larger role than previously thought in the diets of Hebridean Neolithic communities."
The study sheds fresh light on the lives of early farming communities in the Outer Hebrides.
Cultivation of cereals is believed to have been introduced by migrants from continental Europe.
Widespread evidence for livestock has been identified from prehistoric animal remains - also reflected by ubiquitous dairy lipids in pottery organic residues.
Dr Hammann said: "Here, we demonstrate cereal-specific markers can survive in cooking pots for millennia.
"They reveal consumption of a specific cereal wheat that is virtually absent from the archaeo-botanical record for this region - illuminating culinary traditions among early farming communities."
Crannogs were often for domestic use but also provided locations for ritual practice. In the Iron Age they were probably defences against rival tribes.
Some were in very shallow waters close to the shore, while others appear too small to have housed significant structures for long term occupation.
Archaeologists have suggested they may have been built for symbolic reasons - to express a group's social separation from the rest of society or create a special ritual space separate from everyday life.
Dr Hammann said: "The vessels analysed here form an exceptional group, associated with potentially ceremonial contexts and comprising many near-complete vessels.
"The range of vessel forms include traditional Hebridean ridged and non-ridged baggy jars as well as 'Unstan' type bowls and shouldered bowls.
"The Hebridean jars form part of a distinctive Hebridean Neolithic pottery tradition, whilst the 'Unstan' type bowls, found in significant numbers at Hebridean islets, are also found at sites in Orkney, where they are frequently associated with tombs.
"They have also been found on the northern mainland of Scotland."
It is thought the pots were brought to the crannogs having already been in use at domestic settlements in the vicinity.
Dr Hammann said: "Our results probably therefore reflect very localised patterns of dietary behaviour - amongst those people using these crannog sites - that seemingly contrast with plant macro-fossil evidence from other parts of the Outer Hebrides and Atlantic Scotland more broadly.
"Due to the preservation conditions required for survival, along with specific protocols for the concentration and detection of cereal-specific bio-markers, such evidence for cereal processing has unsurprisingly not been detected in the relatively low number of sherds that have been analysed from other Neolithic sites in the Outer Hebrides.
"However, these earlier results, which indicate widespread presence of dairy products from both another islet (Eilean Domhnuill) and a sea stack (Dunasbroc, possibly a cliff top site during the Neolithic), are consistent with a general prevalence of milk-derived products in vessels from this region."
He added: "It is very exciting to see cereal biomarkers in pots can actually survive under favourable conditions in samples from the time when cereals, and pottery, were introduced in Britain.
"Our lipid-based molecular method can complement archaeobotanical methods to investigate the introduction and spread of cereal agriculture."
Crannog sites in the Outer Hebrides are currently the focus of the four-year Arts and Humanities Research Council-funded 'Islands of Stone'.
Project director Prof Duncan Garrow, of the University of Reading, said: "This research, undertaken by our colleagues at the University of Bristol, has hugely improved our knowledge of these sites in many exciting ways.
"We very much look forward to developing this collaborative research going forwards."
Oats were not introduced to Scotland until about 600 AD. But traces of barley porridge have been found in 2,500 year old pots - also excavated from the Outer Hebrides.
Porridge - traditionally oats simmered in milk or water - has been a breakfast favourite in UK homes for centuries.
It is rich in healthy plant chemicals and minerals including copper, iron and manganese - protecting against heart attacks, strokes, diabetes and cancer.
But it took a long time to reach our tables compared to cereals like barley and wheat. Wild oats originated in Western Europe thousands of years ago.
The Romans were first to grow oats to feed horses, mules and oxen. In Medieval Scotland, a lack of sun and high humidity allowed only the hardiest grains to grow.
Far more reliable than wheat or maize harvests in harsh weather, oatmeal - oats that have been dehusked, steamed and flattened - quickly became the staple food for the lower classes.
Local variations such as gruel - a thinner version of porridge - featured prominently for the next 1,000 years.
Today, porridge prepared with water and a pinch of salt is as much a symbol of Scotland as whisky, bagpipes and haggis.
The study is in the journal Nature Communications.