Despite research and the experiences of millions of mums-to-be, it is still unclear exactly why women crave certain foods or even non foods (this is a condition known as Pica) during pregnancy. Some believe that hormonal changes are responsible, or that body recognises its need for certain nutrients. There is no scientific evidence to back these theories, although we know cravings happen but do not yet understand the reason for them.

Pregnancy cravings can start at any stage, but are more common in the early weeks and can change throughout your pregnancy. They can even be a first sign that you are pregnant. As well as cravings, some women experience aversion to certain foods they previously enjoyed, such as tea, coffee and fatty food.

Popular cravings may include curries, sweet, sour and spicy foods, pickles, chocolate and ice-cream; these cravings can be mild or intense. It is important to try and keep the rest of your diet as well-balanced as possible to help keep you and your baby healthy. For the first six months of your pregnancy you will not need to have more calories than you did before you became pregnant, and during the last three months you only need an additional 200 extra calories per day, so you need to make them as healthy as possible and not use pregnancy as an excuse to indulge.

Doctors and health experts advise that as long as what you really, really want is not harmful and is in moderation, pregnancy cravings are not a problem. It is important to maintain as healthy and balanced a diet as possible in pregnancy and not eat too many foods that are high in fat or sugar to avoid excess weight gain; the cravings will pass.

Some of the food items or combinations pregnant women crave are a little unusual but will not actually cause harm. It is the non-food cravings that can be more worrying – these are called Pica. Pica is the practice of craving substances with little or no nutritional value. It is unknown what causes Pica; some speculate that Pica cravings are the body’s attempt to obtain vitamins or minerals that are missing through normal food consumption. These cravings may include coal, soap, newspaper, sponges, stones, baking powder. Sometimes Pica cravings may be related to an underlying physical or mental illness. Pica cravings can potentially be harmful as eating non-food substances may interfere with the nutrient absorption of healthy food substances and actually cause a deficiency. Pica cravings are also a concern because non-food items may contain toxic or parasitic ingredients. If you have odd cravings, which are not food-related, it is important to talk to your GP or health professional for further advice.