“It’s a crock of … well, it’s nonsense,” said Peggy Howell, spokeswoman for the National Association to Advance Fat Acceptance.
Howell and other critics have accused public health officials — and a massive weight-loss industry — of using scare tactics to make America’s weight gain seem like more of a crisis than it is. So how do we know Alabama, and the nation, are really gaining weight?
Every year, the states collect data on public health through a survey called the Behavioral Risk Factor Surveillance System, or BRFSS, a survey conducted over the phone. Among other questions, the survey asks people their height and weight.
Sharon Reese, who directs the survey for the Alabama Department of Health, said the Alabama portion of the survey has a sample size of about 6,000.
“We believe it’s accurate because we see consistency from year to year,” she said.
That data is sent to the Centers for Disease Control and Prevention, which calculates the obesity rate, Reese said.
The CDC computes the obesity rate based on something called Body Mass Index, which is a rough measure of the percentage of fat in a person’s body, calculated using only height and weight.
BMI has often been the focus of criticism. Some say the index doesn’t take into account the fact that muscle weighs more than fat. Others say the use of BMI shifted large numbers of people, suddenly, into the “overweight” category.
“Thousands of people went to bed at a normal weight, and when they woke up the next morning, they were fat,” Howell said. “The cutoff point changed.”
Publications from the CDC point out that BMI produces results that correlate closely to other ways of measuring body fat, such as underwater weighing.
One thing is clear from the BRFSS numbers: More people are crossing from the “normal” category into the “overweight” and “obese” categories. Even if the bar for overweight is set too low, as critics suggest, the survey respondents are reporting higher weights than in past decades.
The BRFSS poll is the CDC’s main data source for assessing the state’s weight — but there is another. The National Health and Nutrition Survey is a nationwide study in which researchers do a physical examination of about 5,000 people and interview them about their health habits. The results of that survey show about one-third of Americans as obese, though the study found that the increase in weight has slowed among men and nearly leveled off among women over the past 10 years.