the problem is NOT the diet. the problem is that her husband is a bully and he is teaching his young child that it is perfectly acceptable to treat mum as a doormat and to speak unkindly and nastily about her, to her and in front of her.
THAT is emotional and verbal abuse that is about POWER, not about what food she gives the child. her husband ONLY uses the food as an excuse for his behaviour. believe me, if it wasn't the food, he'd be emotionally and verbally abusive about something else.
fully agree with carang. your husband is a complete a**h*** and it makes me sick to even read about him in your (very sad) message. be absolutely clear that what he does is totally unacceptable and clearly constitutes verbal and emotional abuse.
for the sake of your children's future and for your own benefit, please do seek professional help and do consider divorce as an option. only the threat of divorce has even a remote potential to wake him up and get real.