Our bodies need energy input via food to perform our daily functions. Macronutrients provide us with this energy. The energy from our foods, are all measured in calories. Once we ingest our macronutrients, our bodies burn them as calories. Here are a few examples to see how all our macronutrients can provide calories.

1) 1 gram of fat gives our bodies 9 calories
2) 1 gram of protein gives our bodies 4 calories
3) 1 gram of carbohydrates gives our bodies 4 calories




Macronutrients are not the same as calories, so 500 calories worth of carbohydrates will affect the body much differently than 500 calories worth of protein.

Calories provide a general indication as to whether we are consuming too much or too little energy, while the quantity and proportions of macronutrients (tied with suitable exercise) will determine whether we burn fat, gain muscle, gain fat, etc.