Question: Are there diminishing returns in the amount of fish in a weekly diet? I know you mentioned eating fish about twice a week. I've been trying to eat salmon once a day. Is there an ideal ratio of fish to non-fish protein you should aim for?   There's not a lot of data backing that up and the data we have is pretty poor quality. But I'm of the mind that the diminishing returns come after one or two servings of fatty fish per week. I think if you're talking about white fish it's different. But I am referring to salmon or mackerel — I think once a week or twice a week is good.    As for white fish — it's not as different from meat as you might think, the real big difference in my view is there are some different, like there's selenium and iodine among other things. The big difference in salmon, mackerel, and other fatty fish, versus lean fish versus meat is the type of fat.    This Q&A can also be found as part of a much longer episode, here: https://chrismasterjohnphd.com/podcast/2019/02/24/ask-anything-nutrition-feb-17-2019/   If you would like to be part of the next live Ask Me Anything About Nutrition, sign up for the CMJ Masterpass, which includes access to these live Zoom sessions, premium features on all my content, and hundreds of dollars of exclusive discounts. You can sign up with a 10% lifetime discount here: https://chrismasterjohnphd.com/q&a