I've been there.
Harder for a 6'5" ex to pick me up by the throat when in a 'roid rage that way. Add in the martial arts training (on my part) and it also made it a damn sight easier to heft him straight out of the front door and hold it closed afterwards. Wasn't actually 100kg at the time, was nearer 75kg, but within a year I'd become absolutely solid muscle underneath the fat, the 200 crunches followed by 200 dragon flags without breaking a sweat type of fit and strong.
Zero UPFs, as much of the highest quality meat, fish and vegetables I could find, everything wholegrain, zero alcohol or sugar outside what was naturally in food, just larger quantities as I was swallowing down my rage at his treatment of me whilst biding my time to slowly, gradually funnel as much of my money as I could get away with into a separate account for when he was finally out of my face. And then the fucker decided to make it easy for me and leave for some woman barely out of her teens but had inherited a flat, so appeared to be a more lucrative target than I was, so disappeared overnight.
Inconveniently enough, I then had a five year long flare of autoimmune disease, stopping me from exercising and I lost pretty much all of my muscle mass whilst having high doses of steroid injections every six weeks whilst going through the ridiculously lengthy process of trying every medication that was cheaper than biologics and having them fail. It's a lot harder to eat less and move more than I thought under those conditions.
Doctors were consistently extremely confused to see very healthy bloodwork - HbAC1 perfect, cholesterol perfect, bone density despite all the steroids perfect. And I was consistently extremely irritated by assumptions that I was bingeing upon biscuits, cakes, crisps, kebabs, burgers and gallons of full sugar Coke all of the time.