The findings are based on 18 slim, healthy people (12 men and six women) who took a fast food challenge for four weeks, and a comparison group, matched for age and sex, who ate a normal diet.

The fast good group restricted their levels of physical activity to not more than 5000 daily steps and ate at least two fast food meals, preferably in well known outlets, every day.

The aim was to double calorific intake and increase total body weight by between 10% and 15% to see if these had any impact on their liver health.

Blood samples were taken before the challenge began and then at regular intervals throughout the study period, to check on their liver enzyme and fat levels.

Liver damage is often identified by symptomless increases in enzymes, of which alanine aminotransferase (ALT) is one.

Usually, higher than normal ALT levels are found in people who regularly drink large amounts of alcohol or who have been infected with the hepatitis C virus. But in a significant proportion of people, there is no obvious explanation.

Too much fat in the liver also indicates damage, and is known as fatty liver.

At the end of the four weeks, those in the fast food group had put on an average of 6.5 kg. Five increased their weight by 15%, and one person put on an extra 12 kg in just two weeks.

Sharp increases in ALT occurred after just one week on the fast food diet, and more than quadrupled from an average of 22 U/l to of 97 U/l over the entire period.

In 11 people ALT rose to levels indicative of liver damage. The increases were linked to weight gain and especially higher sugar and carbohydrate intake.

Only one participant developed fatty liver, but test results from the other participants showed a steep rise in fat content in their liver cells, which is associated with insulin resistance.

Insulin resistance is associated with the metabolic syndrome, a collection of biochemical abnormalities which are linked to an increased risk of diabetes and cardiovascular disease.

No such changes were seen among those who continued to eat their normal diet.

bmj

Include fortified foods in your diet (breads, pastas, breakfast cereals with folic acid). Try some new recipes that include folate-rich foods (orange juice, beans, dark leafy green vegetables, such as spinach). Make taking a supplement containing folic acid a habit. Tell a friend how important it is to take folic acid, especially if she may become pregnant some day.

In addition to folic acid, women of childbearing age should consume adequate amounts of calcium with vitamin D and DHA omega-3, an essential fatty acid and building block of infant nutrition that may promote a healthy pregnancy and prevent late preterm birth.

The National Osteoporosis Foundation recommends that pregnant and nursing women consume 1,000 milligrams of calcium per day and between 400 and 800 international units of vitamin D per day. Vitamin D helps the body absorb and retain calcium. Pregnant and nursing women should consume at least 200 milligrams per day of DHA omega-3, which is the same recommendation for the general population.

Soccer star and new mom Mia Hamm has teamed up with the Society for Women's Health Research to provide women with information about these nutrients. Hamm is featured in a series of television and radio public service announcements, which began airing nationwide in February. A Web site, TheBig3, provides more information on the nutrients.

womenshealthresearch