In reality "only" around 41.9% of US citizens are considired obese. That is stillbhuge and rising.
Source: CDC
Title : National Health and Nutrition Examination Survey 2017–March 2020 Prepandemic Data Files Development of Files and Prevalence Estimates for Selected Health Outcomes
So, just to be clear, if I'm following correctly: the chart is incorrect. The error in the chart is that it ignores that obese people are also overweight, and "extreme obese" people are also both obese and overweight.
So rather than show the obese people as a subset of overweight, and extreme obese as a subset of obese, the chart is adding the percentages together to falsely represent each designation cumulatively.