She is one of the most highly cited scientists in the field of the epidemiology of obesity according to Thomson Reuters[2] and has been called "one of the great epidemiologists" by former FDA Commissioner David A.
After three years and some community college courses in chemistry and biology, Flegal returned to UC to earn a second bachelor’s degree, in food and nutrition.
When a post-doctoral position at the University of Pittsburgh offered little opportunity for research, Flegal completed a second master's degree there, in public health (MPH).
[2][5] In 1994, Flegal and her CDC co-authors were among the first to publish data indicating that the percentage of overweight people in the United States had been increasing from the 1980s onwards.
[9] The study received considerable opposition, in part because its conclusions differed from those of another paper published by senior CDC authors in March 2004.
"[5] Willett was subsequently admonished for his unseemly behavior towards Flegal in an editorial and feature article in Nature, one of the world's pre-eminent scientific journals.
The panel's members suggested that Flegal's meta-analysis paper contained methodological errors, and criticized the selection criteria used for washing out too many people.