Just put more cheese or chocolate on everything you eat.

Works for me.

Earlier in the year I was in hospital for a while, had to have surgery. I went in at 80kg and after 5 weeks was just under 66kg.

I’m 175cm tall, BMI 26.1 (technically over weight, but was very fit) down to 21.6, which is considered “normal” but I felt very skinny and unhealthy.

The BMI thing is a little bit bullshit, since it doesn’t map fitness level.

As for getting back to a healthy weight, take it slow, eat really healthy foods eat mostly nova 1 & 2 foods, some nova 3 and avoid nova 4 if possible.

Also if you have been on antibiotics while in hospital, eat ferments like kimchi or sauerkraut, maybe drink some kombucha to rebuild your gut flora. But take it slow as it can really mess you up if you dump too much in at once.

I had a similar, less severe problem when I started cycling to work (10 miles each way). I was losing weight, and I was getting borderline underweight.

My problem is that if I’m working on something, I’ll just not eat, and that’s really bad if I’m burning an extra 1-2k calories (and I’d end up really low on energy on the ride home). So I scheduled regular snacks, many of them with higher carbohydrate levels than I would normally eat (yogurt + granola, crackers + cheese, etc), and I would keep high protein snacks at my desk (nuts and whatnot). I would make sure to hit my targets for protein and fat, and then go ham with tasty snacks.

When I reached my target weight, I dropped the snacks.

If that doesn’t help, then I recommend what my friend w/ thyroid issues did: drink nutrition shakes (basically adult “formula”). He had a limited appetite, so he would have to get as many calories in as possible when he was hungry, and calorie/nutrient-dense shakes worked because he would just not finish larger meals.