Engaging in healthy diet and physical activity during pregnancy is linked to several enhanced outcomes at birth, according to a University of Adelaide study. The finding is more applicable to pregnant women who are overweight or obese.

Obesity is one of the largest health problems in the 21st century. According to a study by the City University of New York and the University of Wyoming, those who are obese at 25 years of age are more likely to suffer from severe weight problems at the age of 35 years or above. Policies on reducing high infant birth weights should be introduced to fight obesity.

"While it might have been expected that healthier eating and increased physical activity during pregnancy would be associated with differences in weight gain, our findings highlight that weight gain in pregnancy is not an ideal measure of pregnancy health," said study leader Professor Jodie Dodd, from the University's Robinson Research Institute and the Women's and Children's Hospital, in a press release.

Dodd said that healthy eating involves increasing the number of servings of fruits and vegetables, while reducing their consumption of foods rich in saturated fats. On the other hand, physical activity featured 15-20 minutes of brisk walking on most days of the week.

The researchers said that the significant improvements in outcomes for babies include lower incidence of moderate to severe respiratory distress syndrome and reduced stay in hospital.

"Our hope is that by following some simple, practical and achievable lifestyle advice, pregnant women can improve their health and the outcomes for their babies. We would, of course, recommend that these lifestyle changes be adopted as much as possible before women become pregnant," said study co-author Dr Rosalie Grivell from the University's Robinson Research Institute..

The finding is published in the journal BMC Medicine.

According to another study by the University of Adelaide, women who received diet and lifestyle advice during pregnancy gave birth to babies weighing less than 4 kg. The finding is significant because infants with higher birth weight face heightened risk of becoming obese as children or adults.

"Infants born to women who received lifestyle advice were 18 percent less likely to have a high birth weight as compared to infants born to women who received standard care," Professor Jodie Dodd said in a press release.