Nutrients Our Body Needs!

Nutrition Centre

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Macronutrients

are nutrients that provide calories or energy. Nutrients are substances needed for growth, metabolism, and for other body functions. Since “macro” means large, macronutrients are nutrients needed in large amounts. There are three macronutrients:

  • Carbohydrates

    form the major part of stored food in the body for later use of energy. They are also important for fat oxidation and can also be converted into protein.
    Carbohydrates are mainly found in starchy foods (like grain and potatoes), fruits, milk, and yogurt. Other foods like vegetables, beans, nuts, seeds and cottage cheese contain carbohydrates, but in lesser amounts.

    Fibre is a non-digestible carbohydrate found in plant foods. It is an important part of a healthy diet and plays many roles in the body. Fibre may help with bowel regularity and to lower blood cholesterol levels. Fibre can be found in fruits, legumes such as dried beans, lentils, peas, soybeans, nuts and seeds, vegetables and whole grains.
    Canadian women need 25 grams of fibre per day and men need 38 grams of fibre per day. Most Canadians are only getting about half that much!

  • Protein

    makes up most of the cell structure including the cell membrane. Genetic information in the cell is stored as protein in the form of DNA. All the enzymes, that catalyze metabolic reactions in the human body, are protein in nature.
    Protein is found in meats, poultry, fish, meat substitutes, cheese, milk, nuts, legumes, and in smaller quantities in starchy foods and vegetables.

  • Fat

    is used for making steroids and hormones. Cholesterol also makes up the cell membrane and provides a degree of rigidity to it. Fats also serve as solvents for hormones and fat-soluble vitamins.
    Fat is found in meat, poultry, nuts, milk products, butters and margarines, oils, lard, fish, grain products and salad dressings. There are three main types of fat: saturated fat, unsaturated fat, and trans fat. Saturated fat (found in foods like meat, butter, lard, and cream) and trans fat (found in baked goods, snack foods, fried foods, and margarines) have been shown to increase your risk for heart disease. Replacing saturated and trans fat in your diet with unsaturated fat (found in foods like flaxseed oil, avocados, nuts) has been shown decrease the risk of developing heart disease.

While each of these macronutrients provides calories, the amount of calories that each one provides varies.

  • Carbohydrate provides 4 calories per gram
  • Protein provides 4 calories per gram
  • Fat provides 9 calories per gram

Besides carbohydrate, protein, and fat the only other substance that provides calories is alcohol. Alcohol provides 7 calories per gram. Alcohol, however, is not a macronutrient because we do not need it for survival.

The DRI Committee has determined that the composition of a diet that provides adequate energy and nutrients and reduces the risk of chronic diseases is:

  • 45 – 65 % kcalories from carbohydrate
  • 20 – 35 % kcalories from fat
  • 10 – 35 % kcalories from protein

Based on a 2,000-calorie-a-day diet, this amounts to about 225 to 325 grams of carbs, 44 to 78 grams of total fat a day. The DRI (Dietary Reference Intake) is 0.8 grams of protein per kilogram of body weight, or 0.36 grams per pound. This amounts to 56 grams per day for the average sedentary man and 46 grams per day for the average sedentary woman.

Micronutrients

include minerals and vitamins. Unlike macronutrients, these are required in very minute amounts. Together, they are extremely important for the normal functioning of the body. Their main function is to enable the many chemical reactions to occur in the body. Nevertheless, micronutrients do not function for the provision of energy.

For more information on the different micronutrients, their roles and food sources, click on the image.

 

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