Children who drink trendy almond or soy milk are shorter than those who just have cow's, new research reveals.
Three-year-olds that drink three cups of cow's milk a day are on average 1.5cm taller than youngsters given trendy milk alternatives, a study found.
According to the Daily Mail, drinking one cup of cow's milk a day makes children 0.2cm taller than average for their age, the research adds.
While a daily cup of non-cow's milk makes them 0.4cm shorter, the study found.
Researchers believe this may be due to non-cow's milk's lower fat and protein content halting children's growth.
Study author Dr Jonathon Maguire from St. Michael's Hospital in Toronto, said: "Height is an important indicator of children's overall health and development. Many parents are now choosing non-cow's milk for their children, which may have lower nutritional content."
How the study was carried out
Researchers from St. Michael's Hospital in Toronto analyzed more than 5,000 children between the ages of two and six.
Of the study's participants, 92 percent drank cow's milk every day, while 13 per cent had non-cow's milk.
Results, published in the American Journal of Clinical Nutrition, reveal that drinking one cup of cow's milk a day makes children 0.2cm taller than is average for their age.
While a daily cup of non-cow's milk makes them 0.4cm shorter.
Three-year-olds that drink three cups of cow's milk a day are on average 1.5cm taller than those that have the equivalent amount of milk from plant-based or other dairy sources, such as goat.
Youngsters who drink a combination of cow's and alternative milks are also shorter on average.
The study did not examine why drinking non-cow's milk reduces children's height.
Yet, the researchers speculate that youngsters who have non-cow's milk may consume less protein and fat, resulting in reduced growth.
What the researcher said
Dr Maguire said: "Height is an important indicator of children's overall health and development.
"Cow's milk has been a reliable source of dietary protein and fat for children, two essential nutrients to ensure proper growth in early childhood.
"But many parents are now choosing non-cow's milk for their children, which may have lower nutritional content.
"The nutritional content of cow's milk is regulated in the United States and Canada, while the nutritional contents of most non-cow's milks are not.
"The lack of regulation means the nutritional content varies widely from one non-cow's milk product to the next, particularly in the amount of protein and fat."
According to Dr Maguire, two cups of cow's milk contain 16 grams of protein, which is 100 per cent of the daily requirement for a three-year-old child.
Yet, two cups of almond milk typically contain just four grams of protein, which is only 25 per cent of their daily requirement, he added.
The shift towards purchasing non-cow's milk has been relatively recent, therefore little research is available on the impact this has on children's growth, Mr Maguire said.
This makes it difficult for the average consumer to understand the pros and cons of choosing non-cow's milk over cow's for their child, he added.
Mr Maguire said: "If products are being marketed as being equivalent to cow's milk, as a consumer and a parent, I would like to know that they are in fact the same in terms of their effect on children's growth."