Similarly bigger you are you need more fuel even if your aim is to reduce your size. You can't put your body to zero carbs or no fuel. The three macro ingredients carbohydrates, proteins and fats have very different roles to play in our body. Any imbalance of their proportion would lead to waste of expensive food not getting absorbed by the body leading to mere taxing of our body’s biological system.
Carbs are consumable fuel of the body if taken in excess will get converted to fat and will get stored under the skin and in our system as body fat. Fats just enter the system and get stored as body fat. This stored fat is sort of an alien in our body, which is of no use in excess rather it, gives enormous problems and leads to complications. The fat comes in use only when there is an acute energy deficit and the body is overworked with exercise. The fat when used by the body get converted to carbs and then used as energy. The fat never gives energy it self.
Proteins are important building blocks constitute body tissues like skin, muscles, blood, bones, nails, hairs etc. Proteins should never be used for energy purposes. Proteins are used for energy only when our food is imbalanced and carbs are less then the required proportion. If carbs are deficient in diet protein will provide energy. This will lead to more waste materials in our body leading to tiredness, stiffness and mental irritation. One has to understand that human body fat comes into energy cycle only in the last, which is after carbs and protein. When someone goes on hunger strike the persons lose more muscle mass than body fat.
So zero carbs diet means using protein as energy, which is not healthy, and ends up to no positive long-term results. If you want to lose you must have low carbs means not less than 40% and moderate proteins. Zero carbs diet means just proteins and is just waste of money and over taxing your body systems. Let there be balance of Carbs 55% Fats 15% Proteins 30%. Any major imbalance in diet proportions is just junk and will never give you long-term benefit.