There's good news if you're tucking into bacon and eggs this morning - new research says a traditional fry-up is the healthiest way to start your day.

Researchers at the University of Alabama claim a fried breakfast loaded with protein kick-starts the metabolism, making it easier to burn off other meals.

They found mice fed a high-fat meal soon after waking remained healthy.

Those given a carb-rich breakfast, such as cereal, followed by a fatty dinner put on weight, had trouble digesting food and a higher chance of diabetes.

Blood tests also found increased risk of heart disease and stroke.

But Kiwi dietitians scoffed at the findings. Alda Lee said a cooked breakfast would mean eating a high amount of fat, most likely dangerous saturated fat.

Anna Richards said having a fatty breakfast every morning would also see you miss out on vitamins and minerals.

She said a bowl of cereal wouldn't be enough to last until lunch and recommended having protein, such as beans or an egg, or adding yoghurt and fruit to cereal.

The findings also failed to convince diners enjoying a Good Friday fry-up at St Kevin's Cafe on Auckland's K Rd.

"If you have a big breakfast you feel a bit more lethargic," said Tyler Smith, as he polished off two fried eggs, sausage, bacon, eggs and avocado. "But I won't eat much later."

His wife Ming, who was enjoying eggs benedict with bacon and sausage, said she felt less like snacking after eating savoury food in the morning. And friend Kent Dapiere, who was also eating eggs benedict, said a cooked breakfast could be a hassle.

"It takes time to prepare whereas cereal is instant."