The university's Research Institute for Future Food revealed that 96 percent of breastfeeding mothers did not meet the official recommended daily intake of fruits and vegetables - at least two servings of fruits and three servings of vegetables, with each serving at about 80 grams, according to the Centre for Health Protection.

Between 2014 to 2015, the research team collected breast milk from 90 mothers and recorded their diet for three days, including one holiday. The phytonutrient content of the samples were then measured and analyzed.

The results showed a correlation between diet and the level of nutrients in breast milk - particularly phytonutrients such as carotenoids, which are converted into vitamin A, promoting brain, vision and immune system development in infants.

Wong Man-sau, a professor at the department of applied biology and chemical technology, said apart from commonly known nutrients - such as protein and fatty acids - breast milk also contains phytonutrients that can reduce inflammation and play a vital role in the physical development of infants.

"Lacking one or more nutrients may weaken the immune system of infants and may also increase their risk of developing chronic diseases in the future," Wong said.

A correlation was also found between fruit and vegetable intake and breast milk polyphenol content - a powerful antioxidant and anti-inflammatory compound that can reduce the risk of cardiometabolic diseases and bacterial infection, according to Daisy Zhao, an assistant professor of the department of applied biology and chemical technology.

According to a report from the Department of Health, the average daily fruit intake of Hongkongers is 1.1 servings, while the average daily vegetable intake is 1.4 servings - far below the recommendation.