Not with yoga, anyway. Yoga takes effort, but it doesn't burn a lot of calories. I can successfully out-train a shitty diet, and I do on occasion, but I'm cycling & running hours at a time. If I burn 2,000cal running before most people even drag their asses out of bed in the morning (and onto the couch...), then I have no reservations about munching down 2 donuts, then chasing them with a protein drink. Pizza for lunch? Sure. Bike ride for dinner. Sleep, wake at 4am, repeat. 132lbs day after day.