Involving children in meal preparation made food fun and interesting, making them more likely to eat it, she said.
Focus on Food business manager and NZ registered dietician Emma McMichael said the importance placed on convenience meant people perceived there was a big effort in preparing a healthy meal.
"Obviously for most people, it is convenience. For some people it is: 'I don't know what to cook, and I can't think of how I deal with that', and it's the loss of cooking skills. Home economics isn't a popular subject as much anymore and some of those meal preparation skills aren't getting passed down to teenagers."
Food Solutions owner and NZ-registered dietician and nutritionist Fiona Boyle said families had become time poor but it came down to being organised and many people did not have basic skills.
"You learn off the way your parents go about preparing food. If it is not being done in the home, the child can't learn it."
A good meal could be rustled up in 20 to 30 minutes and did not need to be exotic, she said.
"Put aside half an hour a week to plan what your meals are and base your shopping list around that.
"But remember to take into account what you need for school or work lunches and make sure you have everything you need.
"If you are not planned or organised, good nutrition won't usually happen."
Children who grew up thinking takeaways were normal would prefer that type of food, she said.
Toi Te Ora Public Health Service medical officer of health Neil de Wet said it was important to acknowledge there were "lots of different kinds of foods that are considered fast foods or takeaway food.
"For me, it is the whole picture and food environment. Many of the foods in the supermarket, especially the packaged and processed foods, have a surprising amount of sugar."
Food was often aggressively marketed and had become energy dense, which meant "we readily eat more energy than we need".
That was contributing to rising obesity rates as the foods were often high in fat, sugar and salt, while fizzy drinks were "one of the most important contributors of our obesity".
Dr de Wet said long-term obesity had many additional health risks such as high blood pressure, increased risks of heart disease, increased risks of some cancers, joint and sleep problems and type 2 diabetes.
Figures from a New Zealand Health survey conducted between 2011 and 2014 that broke down regional statistics for the first time estimated one in four Bay children between the ages of 2 and 14 were overweight - 9 per cent were obese, with a further 17 per cent overweight.
Another report showed almost one in three adults aged over 15 were obese and a further 34 per cent were overweight.
A McDonald's spokeswoman said its sales figures showed the average New Zealander ate at McDonald's 1.5 times a month.
"Of all the money that New Zealanders spend on food, 24 per cent is spent on meals away from home and ready-to-eat meals. The remainder, 76 per cent, is spent on food consumed at home."
McDonald's had also made significant changes to its menu, developed healthier menu choices and removed 750,000kg of saturated fat each year by switching to a sunflower and canola cooking oil, she said.
It did not advertise to children on TV and showed the healthy choices in happy meals and limited how often toys were shown.
