​The pre-natal and early developmental phases of life can influence the onset of chronic diseases including heart disease, stroke, diabetes and obesity in later years.

The Foetal Origins Theory, pioneered by Professor David Barker, has led to a revolutionary understanding that chronic diseases, often manifested in adulthood, are programmed during pregnancy and the early stages of growth and development. It highlights that a woman's body composition, which is influenced by her diet and lifestyle, before conception and during pregnancy, have important effects on the subsequent health of her offspring and on future generations.

According to this theory, babies born with birth-weights at extreme ends of the normal weight range (either too small <2500gm or too large >4500gm ) have an increased risk of developing chronic diseases in adulthood. The associations between low birth-weight and diseases later in life are thought to reflect foetal programming , the process whereby malnutrition in the womb, and the consequent small body size at birth lead to lifelong changes in the body. Fat babies (i.e. those at the upper end of the birth-weight range), are also at increased risk.

In order to prevent the onset of chronic diseases, it is necessary to improve the nutrition of the foetus (i.e. the baby's nutrition in the womb). A baby's nutrition in the womb depends upon the mother's nutrition through her life and not just her diet during pregnancy.

The establishment of healthy dietary practices before conception not only determines a mother's body composition, it also provides the stores of food that she will bring into pregnancy and make available to her baby. It is hence important that all women and intending mothers-to-be incorporate healthy eating and lifestyle practices prior to, during and after pregnancy to ensure the best outcomes for the baby and child after birth and throughout the lifespan.