    Sentence 1: The number of extremely obese  Américan adults - those who are at least 100  pounds: overweight - has quadrupled since th  1980s to about 4 million .    Sentence 2: The number of Americans  considered extremely obese , or at least 100]  pounds overweight , has quadrupled since the}  1980s to a startling 4 million , the research]  shows .