New mothers need extra support so more breastfeed, government advisers warn.
Breastfeeding is becoming more common
Although 76% of women start out breastfeeding, this falls to 50% by six weeks - and one in four by six months.
The Scientific Advisory Committee on Nutrition said rates had improved, but more awareness of the health risks of not breastfeeding was needed.
The government said a breastfeeding helpline had been set up to offer practical support and information.
The latest recommendations from the committee were based on the Infant Feeding Survey from 2005.
The survey, which has been carried out every five years since 1975, also found that well-educated, professional women aged over 30 who were first-time mothers were the most likely group to breastfeed.
Committee members said there were several areas for improvement.
They said few parents delay the introduction of solids to around six months of age, as recommended, and that labels on commercial weaning foods should be changed to reflect this advice.
Antenatal and postnatal services needed to be more accessible for hard-to-reach groups, the report warned.
In addition, breastfeeding advice and support should be widely available and all health care providers should receive proper training in how to help women who want to breastfeed, the report said.
The committee also called for the provision of adequate infant feeding facilities in the workplace and in public places.
Studies have shown that breastfed babies are less likely to become obese in later childhood and that breastfeeding can prevent mothers having health problems later in life.
Official advice is to breastfeed exclusively up to the age of six months before the addition of solid foods.
The Department of Health has promised £150,000 a year for a national breastfeeding helpline as part of its aim to make breastfeeding "the norm".
Public health minister Dawn Primarolo said the helpline would provide information about breastfeeding and promote and help to sustain breastfeeding by mothers who often encounter problems during the early weeks.
"When it comes to feeding babies, breast is best.
"Our challenge is to help new mums, who choose to breastfeed, through those early difficult weeks and months."
Sue Ashmore, programme director for Unicef UK Baby Friendly Initiative, said: "There is a great deal of evidence to show that mothers who receive support from someone who believes they can successfully breastfeed continue to breastfeed for longer."
Frances Day-Stirk, a director of the Royal College of Midwives, said the helpline was welcome and overdue.
"However, there is also a need for midwives to be given the time to talk to, advise and support mothers with breastfeeding.
"There are simply not enough of them at the moment to enable them to do this effectively."