Recent TV news showed that various food brands are offering low carbohydrate foods due to public demand. That just shows how poorly informed
public can be.The Mayo Clinic (http://www.mayoclinic.com/) tells us that "Every day your body requires certain nutrients, such as carbohydrates, fats and protein, to function properly. Too much of one nutrient or not enough of another can influence your health."
Encyclopedia Britannica (http://www.britannica.com) tells how carbohydrates can be classified, but they are all described as molecules of Carbon, Hydrogen, and Oxygen. "Carbohydrates are most abundant molecules in all biology."
Carbohydrates and oils are means that plants store energy. Few plant fats are saturated.
Fats are also compounds of Carbon, Hydrogen, and Oxygen, but in more complex structures than carbohydrates. The more structural bonds, less liquid is fat at room temperature. Such liquid fats are called oils. Hydrogenating oils creates more hydrogen bonds to make liquids into soft or hard fats. These trans-fats are bad for cardiovascular health. The "essential fatty acids" are ones that human body cannot create from other foods, such as proteins.
Proteins have many structures, but are mostly composed of Carbon, Hydrogen, Oxygen plus Nitrogen. The essential amino acids are those proteins which human body cannot create from other foods.
Of course, foods also contain essential vitamins and minerals. Supplements of these can be beneficial, if not overdone.
High / Low Carbohydrate / Protein diets really miss target. Once minimal needs of each food type are met, real issue is high or low calories compared to those used. If you eat more than your exercise can burn, you gain weight, and vice versa.
Carbohydrates as sugars are fine as nature provides them, but not as refined and concentrated by humans. Like any source of calories, excess consumption leads to body fat. The details will vary, but a five pound bag of fresh fruit contains fewer calories than a typical candy bar.
