This article basically states that we cannot convert fat to energy. This seems wrong. IIRC the body can use different sources for producing energy, from sugar o

This article basically states that we cannot convert fat to energy. This seems wrong. IIRC the body can use different sources for producing energy, from sugar over carbs to fat, however it will use first what is the easiest to convert (sugar) and last what is hardest (fat). All of which is done by enzymes, I believe. They are ignoring body heat completely. When I exercise I do not only breath out carbons, I am also generating a much higher body heat.