That is just a snack between lunch and dinner.
And how much of that? Probably also not enough.
Supplements don't supply basic nutrition, just some supplemental elements and maybe some vitamins, both of which you will get enough with a sufficient and balanced diet.
Based on what I have read in this topic, my diagnosis is malnutrition. I recommend you start eating regularly and enough, otherwise you will be the next entry in the obituary topic, something a lot of us wouldn't like to see.