What an adolescent girl eats today can affect her chances of having children many years later.
Recommendations published by the Britain-based International Federation of Gynaecology and Obstetrics last October emphasised the importance of good nutrition during the adolescent and young adult periods for lifelong health.
The guidelines include eating healthily before, during and after pregnancy, so that the next generation will also be less at risk of being stunted or obese. They would also suffer less from diseases such as diabetes, or conditions like asthma.
According to the guidelines, poor nutrition in adolescent girls and young women compromises reproductive health and increases the risk of adverse pregnancy outcomes for mother and child.
A poor diet from a young age can cause poor ovulation and poor resistance, leading to easier infections, said Dr Christopher Chong, obstetrician and gynaecologist at Gleneagles Hospital. Vaginal infections can cause poor mobility of sperm and even kill sperm.
Dr Lim Min Yu, a consultant at the Clinic for Human Reproduction at National University Hospital Women's Centre, said: "Researchers have also shown that nutritional status can affect reproductive cells before conception, hence improving pre-conception health should be a priority."
However, having proper nutrition is easier said than done.
Dr Chong noted that young people today are consuming more junk food, food with MSG and food with poorer nutrition values.
"High body mass index and obesity can lead to immature eggs and is linked to polycystic ovarian syndrome, which can cause fertility issues," he said.
In fact, poor diet, coupled with rising pollution and stress, increased smoking and alcohol drinking rates, have caused fertility rates to fall all over the world, he added.
Generally, poor nutrition can lead to a higher risk of diminished reproductive capacity, miscarriage, poor foetal growth and premature labour, doctors said.
So, if a woman needs to lose weight, she should do it in a healthy way: exercise, cut intake of empty calories and eat more nutrient-dense food such as milk, green leafy vegetables, eggs, lean meat and wholegrains, said Dr James Lee from Astra Women's Specialists.
A normal, healthy weight optimises a young woman's chance of getting pregnant, he added.
Schools, doctors, nutritionists and the community can help to educate the public on the importance of good nutrition, said Dr Lim.
SEE MIND & BODY