As the main nutrients found in food, macronutrients maintain your body’s structure and functioning. You typically need a large amount of macronutrients to keep your body working properly. But don’t stress: macronutrients come from proteins, fats and carbohydrates, which give your body energy in the form of calories.Macros are typically measured in grams (g) and can be a useful way to track what you’re consuming. Overall, counting macros is a way to focus on the variety of foods you’re eating — and how much of each — instead of counting calories. Even certain diets like the keto diet and the paleo diet use a macronutrient approach. 

Examples –
During digestion, foods that tend to fall into one of the three macronutrients are broken down to be used for different functions. Macronutrients include:

• Carbohydrates -As the main source of energy, carbs break down into glucose and aid digestion and fullness. Carbs include bread, rice, pasta, grains, fruits, starchy vegetables, beans, milk and yogurt. They provide 4 calories per gram.
• Fat – Fats are broken down into fatty acids and glycerol and provide fat-soluble vitamins A, D, E and K. Foods like nuts, seeds, oils, butter, sour cream, mayo and cream cheese provide 9 calories per gram.
• Protein – Protein helps build and repair muscle, tissues and organs, as well as aid in hormone regulation. Foods like meat, poultry, fish, eggs, cheese, cottage cheese, plain Greek yogurt and tofu provide 4 calories per gram.