It's true that eating vegetables is healthy; however, it seems there are limitations to everything. An all-vegetable diet does have its benefits, but researchers are now saying it is not advisable for pregnant women.

A study conducted by the National Institute on Alcohol Abuse and Alcoholism concluded that women who avoid meat during pregnancy increase the chances of their children being hooked on drugs and alcohol, according to the Daily Mail.

Researchers conducted the study on 5,109 women and their 5,246 offspring. Children whose mothers ate meat daily during their pregnancies fared better than those whose mothers abstained from any meat, with the latter twice as likely to indulge in underage drinking and smoking, and three times as likely to use cannabis.

For the study, researchers analyzed the habits of 5,109 women and their offspring. The children of those who ate meat daily during their pregnancies were compared to those whose mothers abstained from meat during that time.

The due dates of the women the researchers observed were between April 1, 1991 and December 31, 1992. When they studied the children's alcohol, drug and tobacco use, they discovered that kids with vegetarian moms showed increased risk of substance abuse.

Dr. Joseph Hibbeln, who led the study, said that reducing meat consumption could actually cause nutritional deficiencies that affect the development of a baby's brain. Most vegetarians actually have a B12 deficiency during their pregnancies, since these are only available from meats and shellfish. Hibbeln said the vitamin was essential for the body to metabolize folic acid - a nutrient essential in the development of a healthy fetus.

'Among Western populations, infants of vitamin B12 deficient mothers have poor brain growth, developmental regression, irritability, thrive poorly and demonstrate residual deficits in cognitive and social development,' he said.

Lierre Keith, author of "The Vegetarian Myth," has drawn similar conclusions from her research into vegetarianism.  She told Women's Health that many women assume much is to be gained from going vegetarian. But in her view, going meat-free can negatively affect mental and emotional wellbeing.

'I hear from vegetarians every day; they have this terrible depression and anxiety, and they don't understand why,' said Keith. 'People think they're eating a beautiful, righteous diet, but they don't realize there's a potential dark side.'