Appeals to authority are a poor tactic

Maybe, but in this case I don't think it's fallacious. She publishes, is cited all over the place, teaches at a well regarded school, and has explicitly and plainly said CICO is wrong when it comes to weight loss.

This[1] is a good summary of a talk she gave about a year ago and in it she talks a bit about the non-CICO factors in weight gain or loss. Here's one example:

“The gut microbiota of those that are lean versus those that have obesity are quite different, so much so that we can often take the gut microbiota out of individuals that are lean and place it in those that have obesity and see weight shifts with no other modifications."

> She is the director of diversity and inclusion for the Nutrition Obesity Research Center at Harvard (NORCH)

Why did I know this before I even looked?

>“The gut microbiota of those that are lean versus those that have obesity are quite different, so much so that we can often take the gut microbiota out of individuals that are lean and place it in those that have obesity and see weight shifts with no other modifications."

Yeah, so all that effects is CO (calories burned). This does not disprove CICO. I see Fatima has a limited grasp of logic.

> all that effects is CO (calories burned)

Not necessarily. In this case I think she is referring to calories that are not absorbed but are excreted.