The Scottish Executive has pledged to step up its fight against childhood obesity following the publication of "truly frightening" statistics.
Ms Brankin described the issue as "a health time bomb"
Figures show that one in five children in Scotland aged 12 is clinically obese.
Deputy Health Minister Rhona Brankin said education was key in raising awareness among youngsters over the ticking health time bomb.
The Scottish National Party urged the executive to set obesity targets.
Public, voluntary and health figures are gathering in Edinburgh for a conference to discuss the issue.
Earlier this year, the executive launched a campaign to improve children's diets and promote physical activity.
It included nutritional standards for school meals, including set levels for fat, salt and sugar and funding free fruit for pupils in primary 1 and 2.
The World Health Organisation endorsed the strategy as an example for other countries to follow.
Ms Brankin described figures suggesting one in five children aged 12 is clinically obese and every third child is overweight, as "truly frightening".
She said: "We cannot sit back and do nothing in the face of this health time bomb.
"Scotland's children are our future and we must offer the building blocks that will help them make healthier choices.
"A lot of the work we are taking forward is based on education and raising awareness. I firmly believe this is the best approach.
"With comprehension comes informed choice and co-operation. Everyone has a part to play in encouraging children to become more active and eat more healthily."
Nationalists are proposing a bill to ban print, cinema and billboard junk food adverts and the introduction of a "traffic light" labelling system.
SNP health spokeswoman Shona Robison said the executive should introduce targets to reduce childhood obesity.
She said: "We have already grasped the nettle in terms of smoking in public places and we must do the same to counteract our poor record on other areas of public health.
"But while the executive has strong words on the matter, it has yet to even set a target for reducing obscenely high levels of obesity in Scotland."
The UK Government is considering whether it should ban junk food television advertising during the day.