Even before you conceive, your diet dramatically affects the health of your child. So watch what you eat, warns Jane Bartlett

Dieting before you become pregnant can put the health of your child at risk.
So says David Barker, Professor of Epidemiology at Southampton University. His latest research shows that the conditions a foetus experiences in the womb are more important risk factors for heart disease and diabetes in adult life than lifestyle and genetics.

This could mean that what you eat before your child is conceived may have a bigger impact on their adult health than smoking and junk foods consumed during pregnancy. Prof Barker’s research suggests that women who diet excessively in the years before they become pregnant may produce low birth weight babies, who are predisposed to heart disease, hypertension, diabetes and strokes in later life. (Low birth weight is defined as less than 2.5 kg,
or five and a half pounds.)

If you’re dieting before you conceive and then try to compensate as soon as you see that blue line show up, it won’t help. The experts say that eating well once you’ve become pregnant doesn’t make up for earlier nutritional deficiencies. ‘If you’re not fighting fit before you conceive, it’s almost too late,’ says Professor Barker. ‘Farmers laugh at the idea of special diets in pregnancy. They know with sheep that you move them to the best fields before they mate. It’s sad that we understand more about this for livestock than for human beings.’ According to Professor Barker, children who are born small and then grow up to be overweight are especially at risk.

The first few weeks of life are crucial for a growing baby

‘So much happens in the first four to six weeks of pregnancy,’ explains Dr Wendy Doyle of the British Dietetic Association. ‘About eighty per cent of cell doublings take place in the first twelve to fourteen weeks. During that time all the major organs are formed: the cardiovascular system, the kidneys, the brain. All this happens before the pregnancy has even been confirmed.’

Experiments with animals have shown that female rats starved of protein for just a few days after mating had offspring with a higher rate of defects. The female offspring were underweight at birth, while males had high blood pressure, shrunken livers and enlarged kidneys.

Dieting can deplete your body of valuable nutrients, especially if the regime is very low calorie or, worse still, faddy, where you eliminate or concentrate on particular types of food. No baby is going to have the best start in life if she’s conceived while you’re eating nothing but cabbage soup.

Going into a pregnancy overweight also presents health risks.

‘It puts you at risk of gestational diabetes and high blood pressure. It’s also more difficult to lose weight after the baby is born,’ says Colette Kelly, nutritional scientist with the British Nutrition Foundation. Conversely, if you are too thin you may find it difficult to conceive because your periods can be erratic.

Shape up in advance

If you need to lose or gain weight, Dr Doyle’s advice is to start shaping up a year before you try for a baby. You should stop dieting for at least three months, preferably longer, before you and your partner get down to serious baby making activities. ‘I think of it in terms of red blood cells. They have a three-month life,’ explains Dr Doyle. ‘I would also recommend taking a pre-conceptual multivitamin and mineral supplement while you’re dieting to maintain your nutritional status and carry on taking it during the conception period. Make sure it contains 400 micrograms of folic acid.’

Shed your excess pounds by increasing the amount of exercise you do, and decreasing portion size rather than eliminating foods altogether. And try to keep alcohol intake down. ‘If it’s a sensible diet the baby won’t be deprived of anything,’ says Kelly. ‘Follow general healthy eating guidelines: eat more fruit and vegetables, plenty of starchy foods like bread and pasta. Don’t cut out milk and milk products, and go for lean meats, fish and chicken.

Always consult your GP if you have any concerns about your weight, before or during pregnancy. Do you need to lose weight before conceiving? Calculate your body mass index with the iVillage Health Calculator

For more information about healthy eating in pregnancy, see our article‘Nice and not the least bit naughty’.