Fact 1: Mammals generate heat mainly by keeping their metabolic rate high.

Fact 2: Excess body weight raises metabolic heat production.

Given the two facts above, answer the question "What raises metabolism?" with the following options: 
- cigarettes
 - Chlorophyll
 - Chemical energy
 - aerobic capacity
 - fossil fuels
 - Fully cooking the oysters
 - smoking cigarettes
 - excess body weight


 

        excess body weight 