The timing of when people eat could have an impact on health, with an animal study showing late night food consumption leads to a spike in blood fat levels.

Eating late at night could predispose a person to diabetes and heart disease, a study suggests.

Researchers at the National Autonomous University of Mexico examined the impact of late night eating on fat levels in the blood of rats.

The results, published in journal Experimental Physiology, showed triglyceride (fat) levels spiked more drastically compared to those of rats fed during the day.

This may be because consuming food in the evening falls out of sync with the body's natural 24-hour body clock, the researchers propose.

"The fact that we can ignore our biological clock is important for survival; we can decide to sleep during the day when we are extremely tired or we run away from danger at night. However, doing this frequently - with shift work, jet lag, or staying up late at night - will harm our health in the long-term especially when we eat at times when we should sleep," said study author Ruud Buijs.

However, an Australian expert says its too early to be linking night eating to heart disease or diabetes.

Associate Professor Amanda Salis from the University of Sydney's Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders says the research is "interesting" but larger studies are needed before people start changing their food habits to avoid eating at night.

"We know that the body metabolises food differently at different times of the day and this study adds a nice piece of that jigsaw puzzle by showing a part of the brain that's involved in mediating that affect," Assoc Prof Salis said.

"But don't change your diet or the times that you eat because you think its going to reduce heart disease because for that we need large scale human intervention or epidemiological studies to really get the full picture."

According to the Australian obesity researcher, some larger studies have actually shown that Ramadan fasting - where food is only eaten when the sun is down - improves blood lipids and markers for cardiovascular risk.

"Basically eating a healthy diet is still the most important thing, plenty of fruits and vegetables, not too much processed foods," Assoc Prof Salis said.