Am late to this but can only echo what everyone else has said about your complete and utter vile, cruel, cold, nasty worthless husband. His attitude isn't normal and, even leaving the whole weight thing aside for a moment as you say your daughters are unaware of this, I can guarantee that what they will be aware of (even if they haven't voiced it) despite no rows in front of them is that their mum is desperately unhappy, that their dad never shows their mum any affection or respect and you really need to think about how that will affect them.
So far as weight is concerned it's a stupid, indefensible, immature and pathetic (yes, he's the pathetic one) excuse. No doubt about it. If you waved a magic wand and lost weight overnight nothing would change. Any "man" vile enough to taunt his wife with boasts of "fucks" isn't going to change his opinion of her because she fits into a smaller dress size. For whatever reason, he holds you, not your weight, in contempt. If he genuinely cared about you, but wished you could lose a little weight, he would be loving and supportive in your dieting efforts ...... going to the gym with you, suggesting long family walks, showing an interest in healthy eating. But of course I know without asking he's done nothing of the sort. If he has a problem with you, that is HIS problem, not yours. Whatever is at the bottom of it, he is too pathetic to accept responsibility for his feelings and to address them in a sensible and mature way.
As if any further proof of his nastiness were required this is a "man" who is prepared to neglect the daughters he professes to love because he is shunning his wife. Maybe he does want to split up with you, after all, relationships do "run their course" for all sorts of reasons, but, except in very extreme circumstances (eg. violence), both parties share a proprortion of "blame". It is never simply one person's fault 100%. By heaping it all on you he is refusing to accept any responsibility for the situation you find yourself in and/or the way he feels. THAT is a totally cowardly way to conduct yourself.
And by the way, I finally lost 4 stone earlier this year after quite some years of feeling unhappy with how much weight I'd put on. I'd previously done bits of dieting but had never succeeded in going all the way and would "slip back". Having done it now and sustained the loss for 7 months so far do you know what ? ...... whilst it's great to feel healthier & fitter, to have more energy, to wear a bikini, to wear size 8 & 10 clothes (instead of 16), to feel comfortable in practically any style of clothing I choose, to have no wobbly bits etc., the most surprising thing (maybe naiively) to me is that I am EXACTLY the same person as I was before (with maybe a little more confidence admittedly). I don't know quite what I was expecting to feel, nor why this should be such a revelation to me, but I'm telling you this because I think it sort of shows that whatever outer shell we wear it makes no difference to the person inside. I really doubt it would make any difference to your husband if you did the same - he'd find something else to harangue you about.
By the way, I dieted for ME. My partner has never criticised my weight though I have been up and down.
I also noted you said he does absolutely nothing. Well, while he continues to treat you with such contempt I'd do absolutely nothing for him either. Why the hell should you wash (and iron) his shitty pants, cook food for him etc. Please tell me that you are not being a skivvy to someone who treats you so appallingly ?