Small weight gain can raise blood pressure in healthy adults

Many people understand the health dangers of large amounts of extra body weight, but researchers in this study wanted to see the impact of a small weight gain of about five to 11 pounds.

"To our knowledge, for the first time, we showed that the blood pressure increase was specifically related to increases in abdominal visceral fat, which is the fat inside the abdomen," said Naima Covassin, Ph.D., the study's lead author and a research fellow at the Mayo Clinic in Rochester, Minn. "Our research suggests that healthy people who are more likely to gain weight in the stomach area are also more likely to have their blood pressure increased."

At the beginning of the eight-week study, a 24-hour monitor tested the blood pressure of 16 normal weight people. Researchers fed them an extra 400 to 1,200 calories each day with their choice of an ice cream shake, chocolate bar or energy drink to increase their weight by about 5 percent. Afterwards, their blood pressure was taken for another 24-hour period. Their results were compared to 10 normal weight, healthy people who maintained the same weight over the eight weeks. Researchers found:

• Those who gained weight had a systolic blood pressure (top number) increase from an average 114 mm Hg to an average 118 mm Hg.
• Those who gained more weight inside their abdomen had a greater blood pressure increase.
• A five to 11 pound weight gain didn't change cholesterol, insulin or blood sugar levels.

The study was conducted in healthy people ages 18-48. Further studies will need to be conducted to see if the results are similar in different age groups, those with a family history of high blood pressure and other groups, Covassin said.

"The public awareness of the adverse health effects of obesity is increasing; however, it seems most people are not aware of the risks of a few extra pounds," Covassin said. "This is an important finding because a five- to seven-pound weight gain may be normal for many during the holiday season, the first year of college or even while on vacation."