Carbohydrates are. There your body's primary energy source not just from sugars and starches, but many other foods too. But, your body also needs enough of protein, vitamins, calcium, grains, and sugars/fats. Also calories.
proteins
To provide energy.
proteins
What you're looking for are Complex Carbohydrates (starches) which are basically just foods with longer sugar strands. Brown rice, whole grains, and pastas are a few examples of starchy foods that provide long lasting energy.
Sugars and starches are essential nutrients in the body. In most cases, they are considered to be the main source of energy for various processes in the body.
Starches are used for energy
All starches and sugars provide energy.
Carbohydrates are major sources energy and fitness
The food you eat obtained the energy contained in it by eating plants, and or eating other organisms which ate plants. Plants obtain energy by a process known as photosynthesis in which they receive energy from the sun (photons) and store it in sugars such as chlorophyll. These sugars are starches and other carbohydrates which can be broken down and the stored energy is released and used by your body.
primary productivity.
True, sugars and starches are the main source of the body's energy.
Solar energy is the primary source of energy for life on Earth. Cellular energy is contained in bonds found in molecules within cells.