it is amazing to me how SURE everyone is that carbs are bad for you.
carbs are, traditionally, the bedrock of human consumption. Hell, we look at the start of society by farming of a carbohydrate source. And frankly, some of the longest living countries have diets where carbs form the backbone of caloric intake. There may be a huge issue with constantly spiking your blood sugar with sweets (i.e. the american way), but just a little thought would show you how ridiculous it is to claim that carbs are the grim reaper.
Example, Japan. Diets here (I live there so will speak where I have direct experience) are extremely carb heavy. In fact, rice forms the backbone of your ENTIRE DAY. Literally every meal has rice as a central part of your caloric intake. Meats, on the other hand, even fish, are not as common. And very few foods outside of restaurants are high fat. Other places, like Italy, have a high carb, high fat diet.
What do most of the long lived countries have in common? their total calorie intake is low! The one thing that has never had any question mark: caloric restriction is the best indicator for long life. Not carbs, not fats, not saturated fats, not any of those. Just eat less. And it will lower all you blood markers simultaneously. Or, if you want, work out a hell of a lot (not this 3 hour a week BS, I am talking 10-15 hours a week of intense exercise). Then you can basically eat anything and your markers will be amazing.
else, you have to find the diet that works for your genetics. For some, that will be low carb. or some, that will be low fat.