Should you consume a lot of fat on a high-carb diet? I hear different things. Pic related shows that consuming fat with carbs lowers the glycemic index/blood sugar spike you get. So you shouldn't eat carbs all by itself. I hear this a lot, even in books I've read.

Yet, besides these images (I'll post more), I've read that fat (specifically saturated) is what causes insulin resistance when eaten with carbs. The combination of saturated fat and carbs/sugar causes things like obesity and diabetes, not carbs/sugar alone. It makes sense, because most sweets/carbs that fat/diabetic people eat are usually also high in fat. Cookies, cupcakes, pie, etc. Even pizza and burgers have fat due to the cheese and meat. You don't hear about people getting fat from just rice or bread with honey.

Also, some of the healthiest people in the world eat high carb, low fat. Look at Japan. They eat rice with every meal and usually just a little bit of fat in a serving of fish.

So what gives? Should fat be consumed with carbs or not? High-fat or low-fat on a high-carb diet?