you'd better (eat).........EAT........ lass fatty food because it's not good for your health
* Note : had better + V(bare ) < ko có "to" > = should = ought to
you'd better (eat) to eat lass fatty food because it's not good for your health
you'd better to eat less fatty food beacause it's not good for your health
you'd better (eat).........EAT........ lass fatty food because it's not good for your health