Ah yes jealousy and maybe also a lack of understanding.
If someone had told me before I understood LT that all they were living on was 3 shakes a day I'd be concerned. And also jealous of their will power and weight loss. I've been there before when I was feeling fat and ugly, my uniform was tight and I was working with this pretty blonde who was 5'10" ish, about 10 stone and really physically fit. She used to go on about how she "needed" to loose weight as she "was fat" and get below 9 stone (despite the fact she must have had loads of muscle weight there too). Standing next to her made me feel like an umpalumpa. Inferior as she was everything I wasn't.
I ended up being less than supportive when she told me she was loosing weight by eating just 1 yogurt a day and 1 slim fast shake. Yes part of me was concerned for her well being as I know that is not sufficient to maintain you being healthy for long, but part of me hated her for being able to stick to it and loosing so much weight so quickly.
I wanted her to fail so I knew she wasn't perfect as she was making me feel less than perfect.
Maybe this is what you are getting from others - jealousy as you are doing what they wish they could. Keep it up and don't let them put you off. I'm sure if you were raising any concerns amongst the professionals someone would say something when you went to collect your shakes. If they are happy for you to continue then carry on.