Women who fall pregnant while dieting are more likely to have a child that could become obese or diabetic in later life, new research suggests.
Following a study carried out using sheep, University of Manchester scientists believe the findings may hold true for humans as well.
The research may also have found a reason why human twins are more likely to develop type-2 diabetes in adulthood.
The team investigated twin pregnancies in sheep, as well as the pregnancies of ewes that received less food around the time the lamb was conceived.
The researchers then looked at tissues from the brains of the unborn lambs to see if there were changes in the structure of the DNA that would alter genes involved in food intake and glucose levels after birth.
Professor of endocrine sciences Anne White said: "We found that unborn twin lambs had changes in the structure of DNA in the region of the brain that regulates food intake and glucose that resulted in an increased chance of diabetes in adulthood.
"Our findings provide a reason why twins are more likely to get diabetes but we have also shown that mothers who don't have enough food around the time of conception may have a child who grows up with an increased risk of obesity."
The research, carried out with colleagues in New Zealand and Canada, is published in the Journal Of The Federation Of American Societies For Experimental Biology.
Although conducted on sheep, the researchers believe their findings are relevant to humans too as they reveal a non-genetic or "epigenetic" way in which the DNA of offspring can be altered.
While the study does not have implications for the treatment of diabetes or obesity, the researchers say it could be important for disease prevention regimes whereby advice on eating is given to women who are planning a family that could reduce future health risks for their children.