Diet Shakes whilst breastfeeding?

[Manhattan]

Hi All

Well, it seems I overindulged during my pregnancy with DD, and I put on about 30 kgs Somehow I managed to drop 20 of that quite easily, but this last 10 just doesnt want to budge!

So, I've been thinking about supplementing my lunch with a shake. I have tried the Biggest Loser range before, and found it worked quite well, and they were quite yummy too

Does anyone know if it is safe to do so whilst breastfeeding? Do they contain some ingredient that I shouldnt be consuming?

Many thanks in advance x

Eta: Also open to alternative suggestions