The three major food groups are carbohydrates, fats and proteins. Not all of the three food groups are found in all foods and different people have different opinions about what proportion of each makes for a healthy diet.
Carbohydrates can be simple or complex. Examples of simple carbohydrates include sugars such as sucrose and glucose. These are relatively small molecules that are absorbed very easily from the digestive system. Complex carbohydrates include starches and longer chain molecules and are found in foods such as pasta and potatoes. Complex carbohydrates are absorbed more slowly, and give a slower release of sugar into the blood. Carbohydrates provide about 4.5 calories per gram.
Fats tend to be large molecules and there are different types, some better for you than others. Saturated fats are found in fatty meats, butters and cheeses and are best eaten very sparingly. Plant foods such as nuts, seeds and avocados are high in unsaturated fats and these are thought of as being generally more healthy. Fats provide about 9 calories per gram.
Proteins are important for growth and repair of body tissues and supply the body with amino acids. These need to be digested but also broken apart in the liver before they can be used. Proteins are found in meat, fish, pulses nuts and dairy products. Proteins supply 4.5 calories per gram.
Carbohydrates can be simple or complex. Examples of simple carbohydrates include sugars such as sucrose and glucose. These are relatively small molecules that are absorbed very easily from the digestive system. Complex carbohydrates include starches and longer chain molecules and are found in foods such as pasta and potatoes. Complex carbohydrates are absorbed more slowly, and give a slower release of sugar into the blood. Carbohydrates provide about 4.5 calories per gram.
Fats tend to be large molecules and there are different types, some better for you than others. Saturated fats are found in fatty meats, butters and cheeses and are best eaten very sparingly. Plant foods such as nuts, seeds and avocados are high in unsaturated fats and these are thought of as being generally more healthy. Fats provide about 9 calories per gram.
Proteins are important for growth and repair of body tissues and supply the body with amino acids. These need to be digested but also broken apart in the liver before they can be used. Proteins are found in meat, fish, pulses nuts and dairy products. Proteins supply 4.5 calories per gram.