With some meds is is just an increase of appetite. But Zyprexa both increases appetite (often to an extreme, I've seen people eating raw flour on this med), and it changes your metabolism and glucose levels. So even managing eating normally, you will gain. Most people gains. Several people not gaining sounds like way too much of good luck. The only people I met that didn't gain on this one was one that was anorexic and had so much control over her eating she basically didn't eat at all, and the other one was on high dose antacid (makes you less fat in combo with Zyprexa). Else than that I met one single person that naturally didn't get fat from it.

The average weight gain I read from this med is 65 pounds. Wow.

Some meds make you burn less calories. It's just fact. Same with some illness. When I wasn't yet treated for hypothyroid, my diet was 700 calories a day. Adding anything, and I would get fat in notime! So yea, the body really can hold back. It does it in many ways. One way is decreasing your activity and even microacitivity, another way is lowering your body temp. It has even more tricks.

Geodon was NOT weight neutral for me. It made me feel like I hadn't eaten for a week. I was crying every day because the hunger was so bad. One day I decided I would give in just once and eat until I was full. When I cooked my 3rd dinner on a row, I realized I will NEVER feel full. I can only eat until I physically can't eat anymore.

Risperdal made me gain weight while fasting. That is also interesting......