I'm somewhat stunned that you don't think the medical community would notice that.
I don't know why you're stunned. The medical industry's not very smart. There's a lot of things that seem like they should be obvious to anyone with half a brain, but which don't get picked up by the medical industry for decades. They're also almost entirely driven by what makes profits for the pharmaceutical industry. Over prescription of antibiotics anyone?
Another example is biopsy. It's been glaringly obvious to me for decades that the worst thing you could do to a suspected cancer is to chop into it - but chopping into it (biopsy) is the first thing quacks normally do when they suspect a lump could be carcinogenic. And, guess what, research has finally found that biopsy (along with other standard procedures) can lead to metastasis (Juratli et al 2014). And it's usually the metastasis that kills people. It doesn't bear thinking about how many people have been killed by the so-called "treatment".
In a couple of decades, maybe someone will think of doing some research into the role of fluid retention in obesity - unless they already have, but you didn't bother citing it.
Juratli, M A, Sarimollaoglu, M, Siegel, ER, Nedosekin, DA, Galanzha, EI, Suen, JYand Zharov, VP 2014, 'Real-time monitoring of circulating tumor cell release during tumor manipulation using in vivo photoacoustic and fluorescent flow cytometry', Head Neck, 36, 1207–1215. doi: 10.1002/hed.23439