Ya know, thinking about what your co-workers said has definitely turned out to be provocative. It didn't start out this way. At first, I read it, there was a clear and immediate impression I had for what I thought your friends were really saying and for a moment considered leaving it at this without reason to be provoked (stimulated) to further thinking on this. But I did (think further and longer) and sure enough, a second, different impression came to me. I'm now somewhere between impression # 3 & #4 and left with the overall thought that perhaps your co-workers themselves may not have been clear or sure how they meant the word when they said it.
At first there were images recalled to mind from somewhere it the past, the familiar Vice Squad lineup of hookers, pimps and johns herded into a caged van by late-night beat walkers pulling off a sting to satisfy their boss' monthly quota. Is this what your co-workers were suggesting? I doubt it, but then again, I don't know. I consulted a dictionary to refresh my own mind.
For myself personally, and possibly due to being a product of the 60s-era action tv programming, and without clarification from your co-workers to go on, would gernally think of definitions #1 and #2 with the thought they are the likely extreme results eligible to evolve from #4. Pretty interesting how definition #3 varies so wildly in comparison, almost like a kinder, gentler, tamed down, watered down, sugar-coated way implying #1 & #2 without actually saying it, in a "dear lucifer, may I kindly point out to you a slight, personal flaw you exhibit in your ways?" LOL. Perhaps your co-workers were gently trying to point out that your pursuit of health through methods such as fasting is ..... slightly flawed because you seem to pursue it with unfailing vigor and diligence?... how ironic is that?