Health. Nearly half of U.S. adults will be obese by 2030, researchers predict, and about 1 in 4 will be severely obese, carrying about 100 pounds of extra weight. In 29 states, more than half of the population will be obese, and no state will have an obese population below 35 percent. In 1990, the prevalence of obesity was under 29 percent in all states, with several states at or below 20 percent. The report was published in the New England Journal of Medicine.