Type 'obesity' in your search browser and you'll find it as "chronic complex disease".
Well, I could somehow agree only with the first two terms but the last one "disease" for obesity blasted me. This definition for me was quite misleading.
But not for WHO!
Overweight is a condition of excessive fat deposits. Obesity is a chronic complex disease defined by excessive fat deposits that can impair health. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
My reasoning tells me that it's NOT a disease!! It is a "condition". And it's an entirely voluntary condition for the vast majority. Just the same as smoking. Would you call a smoking habit a "disease"?