Directly following that, he goes on to totally misrepresent a 2011 study in which groups were assigned diet soda, water, milk, or full sugar soda; the study saw diet soda participants gain less weight than the water group and actually lost fat. (All other participants gained weight and fat.) That's https://pubmed.ncbi.nlm.nih.gov/22205311/ .
If he isn't a crank, he should stop going on podcasts and saying crank things.
And finally, he's a pediatric endocrinologist. Not a specialist in many of the subject areas he makes claims about (cardiology, gastroenterology, nutrition).