Breast milk containing fructose significantly increases a baby's body weight.
A new study reveals that breast milk containing fructose may increase a baby's body weight, muscle mass, and bone mineral content by the time they're six months old.

When it comes to feeding babies, breast milk is considered the gold standard of foods. (Though, we should mention we strongly believe that 'fed is best' and mothers should not be shamed if they are unable to provide breastmilk for whatever reason.)

A new study done by researchers at the Keck School of Medicine in California showed that when breast milk contained fructose, presumably from food or drink the mother ingested, there were adverse body weight associations in their babies.

The research also showed that the participating babies, who were exclusively breast-fed for the first six months of their life, had higher increases in body fat, muscle mass and bone mineral content.

Related: 10 Things You Might Not Know About Breastfeeding

Researchers believe this small study (25 participating mothers and babies) shows an association between fructose in breast milk and adverse conditions for babies, and that it indicates mothers should watch the amounts of sugar they consume when they are breastfeeding. Fructose is not a natural component of breast milk, and is found naturally in fruits, as well as in processed foods and soda.

Lead researcher Michael Goran said that fructose is considered a 'secondhand sugar,' and comes from the nursing mother's diet. Goran is also the founding director of the Childhood Obesity Research Center at the Keck School of Medicine and says that the exposure of higher amounts of sugar to infants and children during periods of growth and development could produce lifelong risk for several diseases including: obesity, diabetes, fatty liver disease, and heart disease.

More, Goran says that sugar exposure could even affect a baby's cognitive development.

A single microgram of fructose, which is about the weight of a grain of rice and equivalent to what is found in an average day's serving of breast milk could increase a baby's body weight and fat five to ten percent. Lactose, which is the main source of carbohydrate energy in breast milk was 1,000 times less than the amount of a microgram of fructose, and its benefits can be compromised by the presence of fructose in breast milk.

Related: Research Shows That Breastfeeding Protects Mothers From Life-Threatening Diseases

According to co-author Tony Alderete, because the first year of life is one of such rapid development and a critical period for building brain networks and cementing framework for a baby's metabolic system, mothers should be careful with even minute amounts of avoidable fructose.

The ingestion of fructose by a nursing baby could 'coach' her pre-fat storage cells to become fat cells, which in turn could increase her risk of becoming overweight or obese.

And so, while new mamas may be sleep deprived and looking for their coffee hit, they should be careful, Goran advises. Many staples of early motherhood, such as Frappuccinos, energy drinks or even cranberry juice cocktails are sources of secondhand sugars and can be passed on to their little ones.

Goran suggests eating and drinking less sugars while pregnant or breastfeeding, and if choosing formulas or baby foods/snacks, to consider ones without added sugars or sweeteners.

Please note, the study was supported by: the Harold Hamm Diabetes Center at the University of Oklahoma Health Sciences Center; National Institutes of Health grants awarded to the Washington University Diabetic Cardiovascular Disease Center; and Mead Johnson Nutrition.