London - It is often said you are what you eat, but what your father ate may also be important.
Research has shown that a man’s weight affects the DNA in his sperm – leading to thousands of changes which could be passed on to his children.
Genes which differ in the sperm of fat and thin men include some involved in appetite control and brain development.
The Danish research could help explain why children of obese fathers are prone to weight problems and why autism is more common in youngsters whose fathers are dangerously overweight. The University of Copenhagen researchers also found that the changes don’t seem to be permanent.
When the team analysed the sperm of six obese men before and after weight-loss surgery, they found that the chemical “marks” began to alter within a week of the operation. This led to their sperm looking more like that of thin men, the journal Cell Metabolism reports.
Researcher Romain Barres said the research could lead to men, like women, being advised not to eat for two during pregnancy.
Daily Mail