The study, published in Frontiers in Nutrition in July, analysed data from 287 healthy European and Pacific women in New Zealand aged 18 to 45.
It compared health indicators among people with morning and evening chronotypes, often referred to as early birds and night owls, over five days.
While participants tended to consume the same amount of calories, eating patterns and timing differed reliably between the two groups.
Morning types consumed more of their daily energy between 3am and 10am while evening types ate more between 8pm and 3am.
Later risers tended to have higher body mass indexes, body fat percentages and abdominal fat along with worse cholesterol and blood sugar markers.
The difference likely came down to how the body processed food at different times during the day, Griffith University professor and co-author Rozanne Kruger said.
"Our bodies best process food and energy early in the daytime," she told AAP.
"When we're in a rest phase, our metabolic health clocks are also in a rest phase."
While both groups tended to eat the same number of calories, night owls often skipped large meals and did more energy-dense snacking late at night.
Lead co-author, University of Massey lecturer and self-proclaimed night owl Marilize Richter-Cottle said the research had inspired her to reflect on her dietary habits.
"I've definitely reflected on my habits, and have started to pay extra attention to mealtimes and bedtime," she said.
Despite being a nutrition researcher, Ms Richter-Cottle said she found it difficult not to have her meals crawl later into the evening.
"I have to be very conscious about my routines, such as getting daylight immediately when I wake up to reset my internal clock earlier, and I try to mostly stick to a six to 7pm cut-off for eating," she said.
"But I don't always achieve this, especially if I let myself stay up later than usual."
Asked what other night owls should take from the study, she advised cutting off food two to three hours before bed, rather than attempting to overhaul natural sleeping patterns.
"It's not just as easy as getting in bed and eating early if your natural rhythm tells you otherwise," she said.
Prof Kruger said the findings should not be interpreted as proof night owls were inherently less healthy and pointed to several limitations.
For instance, the study only included a limited group of same-sex participants and a relatively small pool of early risers.
"I would say that anything about food intake and body weight is not a simple case of people eating too much, or eating too little," she said.
10°C