Sources and references for: Unexplained Weight Gain

Question:

I Eat Less Than Others, But have Gained Weight Anyway

I can't understand why I weigh 112 kg. I think I eat far less than others. When I was 25, my weight was normal, but it has gradually increased to 112 at 45 years age. I am 180 cm tall. My wife is also a little plump, but less so than me. We both try to be restrictive with food.

Sources, references:

1. The personal experience of Gunborg Palme, certified psychologist and certified psychotherapist, teacher and tutor in psychotherapy.