It's well known that the health of a mother during pregnancy affects the health of the baby, but new research suggests that what a baby's forebears ate and how they lived may also have a significant impact.

For example, a study by the Centre on Ageing at Chicago University (US) found that, for girls, the age of your father at the time of conception is a greater influence on how long you'll live than the age of your mother.

For boys it's irrelevant. Another example is some Swedish research published in the European Journal of Human Genetics that found that environmental factors, such as whether or not there was a famine at the time of your father's puberty, had significant effects on diabetes rates in later generations. If this is true the implications are quite profound, because it's not just the health and state of mind of your own parents that influence your health, but also that of your grandparents. So looking forwards, what are the health implications for future generations of today's overweight and stressed teenagers?

Ref: The Times (UK), 20 November 2004, 'Just blame it on granny', J.Burne. www.timesonline.co.uk