But ok, there is a problem with "CICO": Although true, it does psychologically put "CI" and "CO" on an equal footing -- whereas 90% of your attention really needs to be on "CI". The body is very efficient; exercising doesn't burn much. It's more for the purpose of maintaining some muscle mass as you drop weight. But junk food companies like to skew perception ("balance what you drink and do") to make it seem like a Big Gulp would be ok if only you ran more. Yeah, they're happy to shame and mislead overweight people, so long as they keep buying.