People have a lot of strong feelings on this topic, but in my opinion, feeding anemones (and reef tanks in general) is all about a balance between nutritional health and environmental health. As rather delicate, photosynthetic creatures, corals and anemones are more probably demanding in terms of their environment than what's in their bellies. Plus, once a tank is healthy and well maintained for a year so so they start self-generating a lot food via natural stability of bio-diversity and microfauna populations. Sure, feeding/eating is great and can improve growth, but a degraded environment isn't. Not to mention, most clownfish feed their host anemones when they get fed... at least mine do.
Someone can probably post a link to the thread here about the huge RBTA colony tank. I think he said he only target feeds once/month at most.