Eating a bit of food in bed is not bad for you.
But if you eat a lot of food in bed especially a lot of food that is high in calories then it can lead to weight gain and cardiovascular health problems.
I sometimes eat some ice cream or other foods in bed when I'm feeling hungry before I drift off to sleep and it hasn't been a problem.
But never getting up out of bed to go eat can be bad for your health because you need to move around so get up out of bed sometimes and go eat at the table or take the food outside to a patio table or picnic table etc and have your meals there.
During warm weather I like to take my food outside on the patio and eat at my patio table instead of being inside all the time.
The fresh air outside is good for you too.