Because they know when they are full and satisfied. They dont have Control over what they eat. But how much they eat.
<u>Instructions provided by genetic material:</u>
Genes control everything from hair color to blood sugar by telling cells which proteins to make, how much, when, and where. Proteins are found in a wide variety of foods. Plus the human body is able to synthesise them. Unlike carbs and lipids, proteins are made according to instructions provided by our genetic material (DNA).
Also have nitrogen. Our bodies are able to break down the proteins in goods and utilise the nitrogen for many important processes. Carbs and lipids do not provide nitrogen.
Amino acids, lipids, and other carbohydrates can be converted to various intermediates of glycolysis and the citric acid cycle, allowing them to slip into the cellular respiration pathway through a multitude of side doors. As for protein, our bodies don't maintain official reserves for use as fuel. Rather, protein is used to build, maintain, and repair body tissues, as well as to synthesize important enzymes and hormones.
A good old fashioned spanking
Life processes depend in large part on solutions. Oxygen from the lungs goes into solution in the blood plasma, unites chemically with the hemoglobin in the red blood cells, and is released to the body tissues. The products of digestion also are carried in solution to the different parts of the body. The ability of liquids to dissolve other fluids or solids has many practical applications. Chemists take advantage of differences in solubility to separate and purify materials and to carry out chemical analysis. Most chemical reactions occur in solution and are influenced by the solubilities of the reagents. Materials for chemical manufacturing equipment are selected to resist the solvent action of their contents.
