Natasha Marie Harris (31), who drank up to 10 litres of Coca-Cola daily - the equivalent of 1kg of sugar - died in her Invercargill home on February 25, 2010.
Yesterday, Otago-Southland coroner David Crerar released his findings, in which she was found to have died from cardiac arrhythmia.
''When all of the available evidence is considered, were it not for the consumption of very large quantities of Coke by Natasha Harris, it is unlikely that she would have died when she died and how she died.''
Mr Crerar recommended health agencies investigate whether warning labels concerning the amount of sugar and caffeine in soft drinks would give sufficient protection to consumers.
At the inquest, Ms Harris' family said, as Coca-Cola had no warning signs, they did not consider it harmful.
Her partner, Christopher Hodgkinson, told the inquest Ms Harris also smoked 30 cigarettes a day and was aware of the warning labels on the packets and the health hazard involved.
One or more of her children were born without enamel on their teeth, and Ms Harris had had her teeth extracted several years ago because of decay, which her family believed was caused by Coca-Cola.
The coroner noted this should have been treated as a health warning by Ms Harris, who did not like going to the doctor.
On most days during the six months before her death, Ms Harris, who was estimated to drink between six and 10 litres of Coca-Cola a day, often vomited in the morning, had little energy, and was a poor eater.
A daily caffeine intake of 400mg or less was considered safe for a healthy adult, but a daily consumption of 500mg could lead to health problems.
A litre of standard Coca-Cola - Ms Harris' preferred drink - contained 97mg of caffeine and therefore she consumed up to 970mg of caffeine each day.
Mr Crerar found: ''On the balance of probabilities, this being the standard required of a coroner in these circumstances, it is more likely than not that the drinking of very large quantities of Coke by Natasha Harris was a substantial factor that contributed to the development of the metabolic imbalances which gave rise to the arrhythmia''.
A copy of his findings would be sent to the Ministry of Health, requesting warning labels on carbonated beverages give sufficient protection to consumers.
''The hazards to the health of the consumers of excessive quantities of sugar and caffeine contained in carbonated beverages could be more clearly emphasised.''
Coca-Cola Oceania yesterday issued a statement noting the coroner was not certain what caused Ms Harris' heart attack, and saying the company was ''disappointed'' he focused on her excessive consumption of Coca-Cola, together with other health and lifestyle factors, as the probable cause of her death. ''This is contrary to the evidence that showed the experts could not agree on the most likely cause.''
The company would not be drawn into the coroner's recommendations concerning labelling, but maintained that ''the safety of our products is paramount, and our promise is to deliver safe, quality beverages''.
''All of our products have a place in an active, healthy lifestyle that includes a sensible, balanced diet and regular physical activity,'' the company said.
A Ministry for Primary Industries spokesman said the coroner's recommendation would be considered as part of a policy review for foods containing caffeine.
Public consultation on the review would take place in April this year.
Cola drinks, including those containing guarana, had to be labelled that they contain caffeine, but not the amount when it was used as a food additive.
Formulated caffeinated beverages containing more than 145mg of caffeine per litre were required to list the amount of caffeine per serve and per 100ml and carry an advisory statement the product was not suitable for children, pregnant or lactating women, or people sensitive to caffeine.
University of Otago National Addiction Centre director Prof Doug Sellman said soft drinks would be ''more accurately described as fat drinks, given the amount of sugar in them''.
He advocated a traffic-light system for food, and ''Coca-Cola along with all other sugar-laden, caffeine-heavy, soft drinks should have a large red health information label on the product, signalling to people the potential harm from overconsuming the product''.
He was also supportive of a special tax on ''red light'' foods, which would effectively limit consumption and provide additional revenue for the government to deal with health issues.