Final answer:
The nuts mentioned that are kidney-shaped and lower in total fat content are cashews. They are recognized for their relatively lower fat content when compared to other nut options like almonds, walnuts, and pecans.
Step-by-step explanation:
The kidney-shaped nuts lower in total fat mentioned in the question are cashews. While all nuts contain healthful fats and nutrients, cashews are specifically known for having a lower total fat content compared to many other nuts. Walnuts, almonds, and pecans are also nutrient-rich options, but in terms of lower fat content, cashews stand out among the choices provided.