No, they wouldn't and they don't because they're too addicted to dietary fats. That's part of the underlying problem. They would rather live for their passions of the belly than be healthy and fit.
Just as people are too addicted to sin than to live in Our Lord. Our Lord is the only truth but most people still reject Him. Your fallacious thinking is similar to saying everyone will convert to Christ because, as Catholics know, He is the only way to salvation.
Sugar is way more addictive than fats. I can’t eat so much steak but I can probably have too much juice, sugary foods in one sitting if I wanted. Also fats are filling and satiating. I haven’t had a flair up ever since I watched how much sugar I consumed. Notice how the most expensive foods in the grocery store are meat and dairy?
I watched the doctor panel video you posted and they said “sugar cures diabetes”? I’m calling bullsh*t. And the end of the video is Easy. Healthy. Vegan.