Much happier thin. I was a size 16 and now a size 10 (4 stone). While size 16 isn't massive, I'd crossed into "obese" territory (according to BMI). I'm tall so I probably can get away with a bit more weight. Some of my problems about being overweight were definitely psychological (feeling like people would see me differently) but that's probably because I was thin all my life up until I get pregnant with DD.
I'm no longer ashamed to have my photo taken. For years there were no photos of me, even with the kids, which I feel terrible about.
I don't feel embarrassed to exercise where people might see me. I hated the gym and although I did C25k I always felt people were looking at me when out running in public (I'm sure now they probably weren't, but that's how I felt!)
I now enjoy shopping for clothes. For years I wore the same things because I hated buying bigger clothes. Or I'd just buyer smaller versions of the things I liked thinking I'd slim into them. I didn't.
I enjoy going out in my home town when I go home to visit my parents. Even going to the shops I was always conscious of the possibility of bumping into someone from school or that I knew from way back when I was thin. I hated the idea of them seeing me fat!
I'm self employed and have my own business and losing weight has actually improved my ability to work, make good decisions, get up earlier etc. (because I eat healthier and don't feel so sluggish). Food doesn't control my life anymore so I can focus on more important things.
I'm happier in my relationship because I'm no afraid to be seen with my clothes off.
I'm no longer prediabetic and on the fast track to diabetes. Plus my cholesterol and blood pressure are back to normal.
I don't sweat so much! Warm weather was horrible for me (even though I enjoy the sun) because I would just sweat so much, particularly my face which is horrible. I think it's a hormonal thing that happens when I'm overweight, but once I lost the weight I could go out on warm days and not be afraid of sweat pouring off me.
I think maybe I'd have been happier fat if I'd been fat all my life, but I was always tall and thin and it was easy for me to maintain that for a long time. Getting fat was a real shock to the system and I stayed that way for 7 years before I could get my eating under control.