science

If you want a bunch of paper references I recommend
https://www.dietdoctor.com/low-carb/science every statement has a number, and those numbers directly linked to the scientific articles to back the statement

If you prefer to listen to a medical lecture: https://www.youtube.com/watch?v=kDJsxw0uMLM

Or if you'd rather read a detailed medical textbook https://shop.elsevier.com/books/ketogenic/noakes/978-0-12-821617-0

The nut of it is, most of the modern non-communicable diseases are based in sugar and carbohydrate consumption. The world has about a billion people with type 2 diabetes documented, and that is strictly because of excess carbohydrate consumption.

Of course there's more nuance, inflammation plays a significant factor, and combining fat and carbohydrates at the same time create cellular inflammation due to the Randall cycle (not a cycle) cross inhibition.

There's excellent work going on about the impact of constantly elevated insulin levels, and how that causes most of the manifestations of metabolic disease. And insulin levels are directly driven by carbohydrate consumption, persistently snacking all day means all day elevated insulin.

Most people would be better off eating a whole food diet, no processed foods, nothing from a factory. That eliminates most of the easy sugars, most of the carbohydrates. If somebody wants to eliminate even more, they could try out a low carb, or even a ketogenic diet or even a zero carb diet.