See also my multiple blogposts on resistant starch.

I think the western weight-loss industry targets all forms of carbs almost indiscriminately. Many commentators exclude fiber. Some exclude fruit sugar. My view is kinda mainstream in my focus on table sugar and starch.

1. table sugar and derivatives are universally condemned and should be taken in moderation. Table sugar can affect heart and t2dm.
   • Many juice products have tons of added sugar
2. fruit sugar — is widely considered similar to table sugar but I seriously doubt it. No evidence suggests fruit sugar cause weight gain. In my case, when I eat lots of sweet fruits, my weight doesn’t increase. Note fruit is a major source of sugar since my daily intake is 5 times higher than average
3. starch — I find it quite fattening, but I believe the calorie density is below half of fat. Most people tend to eat many many grams of starch so it is probably responsible for weight gain.
4. dietary fiber — there’s plenty of research showing these carbs are not absorbed, but still most calorie numbers treat it same as table sugar !