Outlook: Obesity Epidemic

FEBRUARY 01, 2008
Susan Farley

Ms. Farley is a freelance medical writer based in Wakefield, Rhode Island.

Fatty Liver on the Rise

A new study has shown that diets loaded with foods high on the glycemic index (GI) may be causing fatty liver in mice. These findings may be linked to the increase in the number of cases of fatty liver disease in Americans— another by-product of obesity.

These high-GI foods include white bread, white rice, and most prepared breakfast cereals, which rapidly raise one's blood sugar level. Low-GI foods include vegetables, fruits, beans, and unprocessed grains that raise the blood sugar level slowly.

As fatty liver was becoming more common in Americans, many physicians attributed it to alcoholism—but that would not explain the increase in pediatric cases. Previously a rarely reported condition in children, today it is estimated that between 25% and 50% of overweight kids will have it. As these kids grow into adults, the fatty liver condition will become full-blown liver disease. The study authors are likening the rise of this condition to the increase in type 2 diabetes seen in the 1990s. The study results appear in the September 2007 issue of Obesity.

Heart Suffers When Overweight

A data review indicated that even when blood pressure (BP) and cholesterol are lowered, the heart is still at risk if an individual is overweight or obese. The study data included >300,000 individuals, 18,000 of whom had heart attacks or died during the study.

Once the researchers accounted for age, sex, physical activity, and smoking, they determined that overweight individuals had a 32% greater risk of heart disease and obese individuals had an 81% greater risk. After adjusting for healthy BP and cholesterol in the study group, they found that overweight individuals still had a 17% increased risk and obese individuals had a 49% increased risk. The study appears in the September 2007 issue of Annals of Internal Medicine.

Lose Weight Before Getting Pregnant

Obese women are 40% more likely than normal-weight and overweight women to have stillborn infants—fetal death in the 20th week or later. Black women have an even greater risk— 90% higher, compared with their white counterparts.

The reasons include the fact that obese women are more likely to have diabetes and high blood pressure during pregnancy. Another factor may be the increased lipid levels among obese women, which narrow blood vessels and promote blood clotting in the fetus' blood supply. Physicians advise losing weight before becoming pregnant. In fact, the larger the woman, the greater her risk of stillbirth—extremely obese women are twice as likely to have a stillborn infant as normal-weight or overweight women.

In a related study, the researchers found that the endometrium has a part in the fertility of overweight and obese women. It is possible that excess weight affects the endometrium where the fertilized egg implants. Among women undergoing fertility treatment, 45.5% of normal-weight or underweight women had pregnancies lasting beyond 20 weeks per cycle of treatment, and 38.8% of women who were overweight or obese went beyond 20 weeks of pregnancy.

Within the study group of 2656 women, the rates of miscarriage and ectopic pregnancy increased as body mass index increased. According to the study authors, the extra weight creates an "extraovarian detrimental effect and its correction could improve the reproductive outcomes in overweight and obese patients."

Several Risk Factors for Childhood Obesity

One of the biggest factors in a child's risk of becoming obese is the mother's weight. Other factors include the amount of television watching and whether there is a rapid weight gain during early childhood. According to a New Zealand study, the 3 most significant factors are:

  • Having an overweight or obese mother
  • Being a girl
  • Watching too much television (>3 hours is associated with 5% more body fat than in those who were limited to 1 hour)

The researchers warn that children begin to show signs of being overweight/obese early in life; therefore, strategies to combat weight gain should begin early as well.