The Topeka Tubby Theory of Obesity

1-Chronic Obesity is due to dysfunction of Leptin and Insulin

Insulin peripherally is anabolic. It promotes constructive metabolism. Insulin will store fat in adipose and glycogen in muscle and liver.

Insulin centrally is catabolic. (like Leptin) Insulin breaks down molecules to release energy.. 

Low Leptin increases food intake and suppresses energy expenditure. (Youdim p6).

"Leptin is an important signal for starvation." 

High Leptin reduces food intake by inhibiting NPY/AgRP neurons and stimulating the alpha-MSH neurons. (Except in the OBESE who become Leptin “resistant". Only LEAN individuals appear to be regulating body weight.) 

Centrally, Leptin and Insulin share same feeding inhibitory and thermogenic pathways.

Here is rest of theory link