slim fast stomach ache?

[choochoomcgrew]

So I'm not a yo yo dieter, I eat pretty healthily (low carb but not extreme, will eat sweet potato, some granary bread once a week ) and I exercise at least 3 times a week.
I'm a size 12 but no idea what I weigh. But my clothes look crap and I obviously need to lose a bit.
I bought some slim fast shakes. Reason being is how busy I am, I think they'd fit into my lifestyle well for breakfast and lunch.
So day one, first shake, horrible stomach ache!! Wasn't what I expected at all.
It's passed now, and this is the first time I've ever had something like this so could that be it?

[Sugarpiehoniebunch]

I started using slim fast shakes and snacks last week and I did get stomach problems to start with but it's all cleared off

[Millli]

If you eat really healthily then I wouldn't go putting fake food like slim fast in your body. Not surprised you got a tummy ache