Loss of energy, weak muscles and fatigue are all the symptoms of deficiency of carbohydrates and proteins.
Low energy levels, fatigue, weak muscles are all the signs of low intake of carbohydrates and proteins. Taking very little or no carbohydrates and proteins in the diet will lead the body to switch to another fuel source in the body. In such a case, the body starts utilizing proteins and fats. When proteins are utilized, all muscles including muscles of the heart become weak.