The word "Diet" suggests restricting your intake, but the only reason to restirct your intake is if you are filling yourself with low-nutrient food. If your focus is on consuming plant-based unprocessed foods you can eat all you want while giving yourself plenty of energy, and moving your weight in the direction (up or down) of your ideal weight. These foods will automatically provide you with the proper proportions of carbohydrates/proteins/fats.
If you feel need to restirct, minimize or eliminate your refined and processed foods, your animal based foods, sweeteners and artificial ingredients. If you are putting the right foods into your body, it will respond by telling you what it needs and how much it needs. If you crave sweets, eat fruit. If you run out of energy increase the whole grains, beans and nuts you are consuming. If you're hungry then eat. For thousands of years the body has functioned properly to make people feel these sensations for a reason. It just couldn't have anticipated the huge surge in processed foods and artificial ingredients of the past century.
It's easier to achieve than you may realize... your palate will adjust rather quickly.