What percentage range of fast-food kilocalories comes from fat?

The correct percentage range of fast-food kilocalories that comes from fat is indeed in the 40-50% range. Fast foods are typically high in calories and often contain significant amounts of fat due to the cooking methods and ingredients used, such as frying and high-fat meats or cheeses.

In many fast-food items, fat contributes to the overall energy content to a great extent, with items like burgers, fried chicken, and other fried or creamy items often exceeding these levels. A substantial proportion of fast food is formulated to be palatable and satisfying, which can often lead to elevated fat content as a way to enhance flavor and mouthfeel.

It's essential to understand that while not all fat is detrimental to health, the types of fat commonly found in fast food (such as saturated and trans fats) can have adverse health effects if consumed excessively. Thus, the high percentage of kilocalories from fat in fast foods is a convenient statistic that reflects common dietary practices in fast food establishments.