Consumer NZ senior writer Belinda Castles said the results were disappointing.
She said when Consumer NZ looked at breakfast cereals marketed to children in 2008 and 2013 it found many products were high in sugar and salt and low in fibre.
"Our latest survey has found companies have cut the sodium but it's a different story when it comes to sugar."
"Low-sugar options remain far too few. It's not like it can't be done."
Auckland University nutrition expert Dr Helen Eyles said high sugar foods did not keep kids full for long like whole foods did.
"It means their blood sugar won't be as steady over the day so they will get hungry much quicker and won't be able to concentrate as well. They might act up because they are hungry."
The National Institute for Health Innovation senior research fellow Dr Helen Eyles said evidence now showed too much sugar over a lifetime was related to obesity, diabetes and even cardiovascular disease. Tooth decay was also a problem.
World Health Organisation sugar guidelines recommend no more than 12 teaspoons of added sugar per day and reducing that to six teaspoons to maximise health benefits.
"So if a cereal has three teaspoons of sugar per day per serve, then that's a good contribution towards those 12 teaspoons."
Dr Eyles said children's breakfast cereals had grown dramatically in 30 years and were directly marketed towards kids.
"They use cartoons and all sorts of strategies to get kids to want to buy them and to pester their parents to buy them. It's not protecting our kids.
"The ability for parents and kids to make healthy choices is harder and harder with our food environment so from that perspective they are getting a raw deal."
Kellogg's senior nutrition manager for New Zealand and Australia Dr Gina Levy said Kellogg's was constantly looking at ways to reduce sugar.
Dr Levy said 70 per cent of the its range was rated four to five stars in the Health Star Rating system and high sugar cereals should not be everyday foods.
"We have some of the highest fibre cereals in the market which have real functional benefits for children and adults but we are working on it. It's not off our radar."
Anne-Marie Mackintosh, nutrition manager at Nestle, which includes the Uncle Tobys range, said the company had systematically reduced sugar and sodium and increased wholegrain and fibre in its breakfast range during the past eight years.
One example was the Nestle Milo Duo which rated 3.5 stars for its high fibre, low sodium and decreased sugar levels, though these were still two teaspoons per serving.
"People choose chocolate-flavoured cereals for taste, and there comes a point where you can't reduce sugar without significantly affecting the flavour," she said.
"As dietitians generally agree that foods should be assessed as a whole, rather than looking at one nutrient in isolation, we've focused on making the overall cereal healthier while keeping the taste people like."
A Countdown spokesman said Home Brand was working with the NZ Heart Foundation on sugar reduction targets for its cereals.
Once these were reached "we will work on reformulating our own brand products in this category, including the Health Star Rating".
