Final answer:
About 25% of the body's chemical energy is used for physical activities, with less than 10% of energy intake used for daily work; the rest is converted to heat or stored. The basal metabolic rate accounts for about 75% of calorie consumption.
Step-by-step explanation:
Only about 25% of your body's chemical energy is used for movement such as lifting, moving, and digging. The remainder is primarily converted into heat, which is used to maintain our body temperature. Interestingly, the body's efficiency is even lower for overall daily activities, with less than 10% of energy intake used for work, while over 90% is transformed into heat or stored as fat. Furthermore, around 75% of consumed calories are used just to sustain basic body functions, known as the basal metabolic rate, with the liver and spleen consuming a significant portion of this energy.