Do you know that there are 9 Calories in 1 gram of fat but only 4 Calories in 1 gram of Protein or Carbs?
Limiting the amount of fat in your diet will more drastically limit the amount of calories you eat compared with the same amount (grams) of carbs and protein you eat.
The goal is to have a balanced diet and you should shoot for the following dietary recommendations:
Calories from Protein (10% to 35%)
Calories from Carbohydrates (45% to 65%)
Calories from Fat (20% - 35%)