Countdown is bringing in an age restriction for buying energy drinks from its supermarkets.
From early September, people will need to be 16 or older to buy them.
Countdown said it was introducing the age restriction in response to the concerns about the impact the high-sugar and highly-caffeinated drinks have on children.
Energy drinks were not recommended for young people and already carried warnings on packaging, its spokesperson said.
Health advocate Robyn Toomath said other supermarkets should follow suit as the restriction would reduce diabetes and tooth decay.
"Marking these as products that need to be restricted has two valuable roles, one that it stops the amount of sugar that kids are consuming, but it also indicates that these are not necessarily health items for consumption."
Ms Toomath said she hoped the government would introduce tighter rules on sugary drinks, including putting taxes.
However, New Zealand Beverage Council, a group representing beverage manufacturers, said it was disappointed at Countdown's decision.
Spokesperson Stephen Jones said energy drinks were fit to consume in moderation, and the restriction could make children crave them more.
"This really is a case of a solution looking for a problem.
"Independent research from Food Standards Australia and New Zealand shows that energy drinks contribute less than three percent of the overall caffeine intake of young people aged between nine and 15.
Mr Jones also said energy drinks contained no more sugar than a wide range of other products.