The biggest scare tactic used by yo-yo dieting dissidents involves threatening the dieting crux– the metabolic rate. Health experts once believed that yo-yo dieting could create metabolic changes that led to diabetes. An investigative group at Harvard University recently tested this theory.
Researchers examined 47,000 women. They concluded that yo-yo dieters, defined as those who lost and regained up to 20 pounds at least three times in four years, were no more likely to develop diabetes than were other women of the same weight who were not yo-yo dieters.
A report in the Tufts University Health & Nutrition Letter also found no link between blood pressure and yo-yo dieting. Blood pressure is very sensitive to changes in weight; if you gain or lose as few as 10 pounds, your blood pressure can go up or down consequently.
In the report, scientists from the Harvard School of Public Health and Brigham Women’s Hospital have found that in terms of high blood pressure– a major risk factor for heart disease– yo-yo dieting is not as risky as most women imagine.
The scientists in this study questioned roughly 48,000 women about their dieting habits and then followed the group for four years to see whether they developed high blood pressure. During this study period, nearly 80 percent of the women lost weight at least once. Twenty percentof them lost and regained 10-plus pounds three times or more.
At the conclusion of the study, about 1,100 of the women did develop high blood pressure. However, the high blood pressure was not linked to their weight changes.
Yo-yo dieting still has its persecutors. One study published in the Journal of the American Dietetic Association warns that yo-yo dieting may impair immune function.
Dr. Cornelia M. Ulrich of Fred Hutchinson Cancer Research Center in Seattle Washington, and her team, studied 114 healthy, overweight, sedentary, postmenopausal women. The researchers found that the immune function of the natural killer (NK) cells was significantly lower in those who had ever intentionally lost 10 pounds or more compared with those without a yo-yo dieting history.
Nevertheless, Dr. Ulrich contends that, “There are clear health benefits to reducing body weight among those who are overweight or obese.”