The World Health Organization is updating its growth rate charts to better reflect how breastfed babies put on weight.

Current charts are based on research from 20 years ago for bottle-fed babies, who put on weight more quickly than those who drink breast milk.

The updated charts are meant to help parents and health-care professionals monitor weight gain in children.

Pediatricians recommend breastfeeding infants for the first six months.
Pediatricians recommend breastfeeding infants for the first six months.

The new guidelines reflect data from more than 8,000 children raised in six countries where breastfeeding and proper diets are common and infectious diseases are well controlled.

Current charts suggest a healthy one-year-old weighs between 10.2 kilograms (22.5 pounds) and 12.9 kilograms (28.5 pounds).

Under the new guidelines, healthy weights drop to 9.5 kilograms (21 pounds) to 11.8 kilograms (26 pounds).

WHO encourages breastfeeding

Pediatricians recommend breastfeeding because the fluid meets a baby's nutritional needs, and contains antibiodies that help babies fight disease and infections.

In 2005, the Canadian Pediatric Society shifted its guidelines to recommend breastfeeding newborns exclusively for the first six months and to continue breastfeeding for two years or more.

Statistics Canada from 2003 suggested 17 per cent of women who had a baby in the five years before the survey fed their babies exclusively from the breast for six months, but the trend is rising.