Your appetite may have been programmed in your mother’s womb.

Your mother’s diet while you were in her womb can permanently change your appetite levels and where fat is deposited on your body, all the way into adulthood.

Who would have thought that either increased or decreased levels of nutrition before birth could lead to an increased risk of obesity? Until recently, not many people would have thought it possible, but it looks to be true. If your mom ate too much or too little, you may be “programmed” to have a higher chance of obesity, diabetes, high blood pressure and heart disease.

And you are not affected just by your mother’s diet. You may also be affected by your grandmother’s diet! This research was on rats; time will tell if it applies to humans too. The research showed the grandchildren of rats fed an inadequate diet during pregnancy were more likely to become obese and insulin resistant. Amazing.

It’s not just diet. Smoking can “program” you for obesity too. If your mother smoked you have a higher chance of being obese. By age 33, the children of smokers had about a 40% higher chance of being obese than the children of non-smokers.

Early evidence for The Womb Threat came from tragic circumstances.

During the winter of 1944-45, Dutch citizens experienced a period of starvation called the Dutch Hunger Winter. The German administration put an embargo on all food transports to the western Netherlands. It was a harsh winter and adults found it difficult to find more than 1000 calories of food a day. Approximately 30,000 people starved to death before the famine ended in 1945.

Some good did come out of this horrible situation. The Dutch kept excellent medical records, which allowed for a very interesting study on how the mothers’ nutritional levels affected the health of their children.

What they found was fascinating. Mothers exposed to famine in the first two trimesters had children who were heavier over their lifetime than the children of mothers who didn’t face famine or who faced famine in the third trimester. Not only were they heavier, they had a lot of other health problems too.

The idea is that the fetus adapts to a limited supply of nutrients, which permanently alters its physiology and metabolism, which could increase the risk of disease and obesity in later life.

How can this happen? A fetus and its mother share the same environment. It’s easy to see how if the mother isn’t getting enough calories then the fetus can’t get enough calories. But there’s more to it. The mother’s hormones can reach the fetus too. And the mother’s hormones can change the development of the fetus.

That’s why these effects can be passed generation to generation without involving genetic changes. Stress is a good example of this chain of events. If the mother is under stress, the fetus may be programmed to be more sensitive to stress. Once born, the child will grow up to be a more stressed adult. And the cycle can start all over again. No genetic changes are involved at all.

As surprising as it sounds, obesity can start in the womb.