Like I said, malnourishment in Canada is largely the result of bad choices by individuals rather than a systematic problem with society.
Poverty, and bad choices by those who are poor, are quite often linked to systematic problems within society, and is a systemic problem in itself. How many aboriginals are malnourished? Or elderly who have little/no income and are unemployable? These are systemic problems. Thus, Canadians, the government, NGO's etc. can do things to help these problems via many means, whether economic, social, political/legislative etc.
Kids in toxic home environments may need to be removed from the home.
In drastic cases yes, but taking a kid away from their family is an extremely traumatic experience for the child and family, and foster homes and (especially) group homes can be really crappy places to live. This causes major damage to the child for the rest of their lives, so it has to be a last resort. The government and social services should try to support and help improve "toxic home environments" in every way possible before the child is removed.