Nutrients are divided into 6 classes. The 6 nutrient classes are in turn divided into Macronutrients and Micronutrients.
The Macronutrients are
Carbohydrates are plentiful in bread, rice, candy and pasta. It’s the most debated of the macronutrients when it comes to diets, some say eat loads some say avoid them. A carbohydrate contains 4 calories (kcal) per g or 16 KJ per g.
Proteins are plentiful in meat, egg whites, and some in beans and nuts. Protein contains 4 calories per g or 17 KJ per g.
Lipids is another word for fat, or fatty acids. They can be found in oils, butter and egg yolks. Fat contains 9 calories per g or 37 KJ per g.
Water is the only macronutrient that does not contain any calories.
The micronutrients are
Vitamins are vital for physiological processes in our bodies. Vitamins do not contain any energy.
Minerals, the same that can be found in the periodic table in chemistry class, are important for normal physiological processes in our bodies. Minerals do not contain any energy.
Alcohol is not a nutrient, but it still contains calories. A g of alcohol contains 7 calories. Alcohol contains 29 KJ per g.