SEPTEMBER 2007

A number of researchers contend that an individual's battles with middle-age spread, hypertension, and diabetes, can be traced back to their mother's diet during pregnancy. This month, Kaiser Permanente researchers report in the journal Diabetes Care that children who consumed an excessive amount of sugar in the womb—because their mothers' mild diabetes caused high blood glucose levels—were nearly twice as likely to become obese by elementary school as those whose moms had been successfully treated for severe diabetes. Another study found that women who followed a high-protein Atkins-style diet had children who much later were unusually sensitive to stress, which is associated with heart disease and diabetes. The implications of this are enormous.

Scientists now believe that after the initial construction of DNA at conception, a baby's genes are programmed a certain way --switched off or on, depending on the conditions in utero. For example, cells may be wired to sock away fat if they're bathed in too many or too few nutrients -- or to release it readily for fuel if given just the right amount. Underweight newborns appear to have systems unable to cope effectively with glucose, which makes them more prone to obesity once they're happily enjoying a fast-food lifestyle. "We first found in the 1980s that people who were born at low birth weights to poor malnourished mothers tended to have high rates of heart disease, stroke, and diabetes," says David Barker, a professor of medicine at Oregon Health and Science University in Portland, who was the first to suggest that fetal programming can lead to chronic disease.

Women who are overweight when they become pregnant risk developing the abnormally high blood glucose levels associated with gestational diabetes. As this sugar-rich blood passes through the placenta, the baby adapts, even becomes "addicted", to this uber-sweet plasma. The baby might be programmed to crank out too much of a "hunger" hormone, leptin, for example, and his/her overfed cells may be less sensitive than they should be to insulin, which normally enables cells to use glucose for energy. Both types of hormonal programming may leave the child with a tendency to overeat that is difficult to reverse. The Kaiser Permanente study found that even women whose blood sugar levels fell into the upper range of normal, 122 to 140 milligrams per deciliter, might benefit by lowering those levels further. Their children were almost 30% more apt to be fat by age 7 than those born to women with lower blood sugar levels. A St. Louis University study found that when compared with those who gained 15 pounds, overweight women who gained 25 pounds or more had more than twice the likelihood of giving birth to large babies, who are at increased risk of becoming obese and diabetic adults.

Too much protein can have adverse consequences, too. In MAR2007, Scottish researchers released the findings from a study of 70 adult offspring of a group of women from Motherwell, Scotland who were told in the 1960s to eat a pound of red meat a day during pregnancy to prevent high blood pressure. When asked to perform such challenging tasks as public speaking and mental arithmetic, these adults produced excessive amounts of the stress hormone cortisol. High cortisol producers tend to develop hypertension and carry fat around the abdomen, which increases the likelihood of heart disease and diabetes.