What is a nutrient? Oxygen? Carbohydrates? Water?

By | March 13, 2012


My nutritionist has been talking about nutrient dense foods and I’ve been curious about optimal nutrition for a long time. What is a nutrient, and can too much of any nutrient harm you?

A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism’s metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy. Methods for nutrient intake vary, with animals and protists consuming foods that are digested by an internal digestive system, but most plants ingest nutrients directly from the soil through their roots or from the atmosphere.

Organic nutrients include carbohydrates, fats, proteins (or their building blocks, amino acids), and vitamins.

Inorganic chemical compounds such as dietary minerals, water, and oxygen may also be considered nutrients.

A nutrient is said to be “essential” if it must be obtained from an external source, either because the organism cannot synthesize it or produces insufficient quantities. Nutrients needed in very small amounts are micronutrients and those that are needed in larger quantities are called macronutrients. The effects of nutrients are dose-dependent and shortages are called deficiencies….

An inadequate amount of a nutrient is a deficiency. Deficiencies can be due to a number of causes including inadequacy in nutrient intake called dietary deficiency, or conditions that interfere with the utilization of a nutrient within an organism.

Some of the conditions that can interfere with nutrient utilization include problems with nutrient absorption, substances that cause a greater than normal need for a nutrient, conditions that cause nutrient destruction, and conditions that cause greater nutrient excretion.

Nutrient toxicity occurs when an excess of a nutrient does harm to an organism.


It’s all about the balancing act. Notice that carbohydrate is a nutrient, and one of the big three macronutrients.

What is a carbohydrate?
Carbohydrates are one of three macronutrients: carbohydrate, protein and fat. They contain carbon, hydrogen and oxygen atoms. Carbohydrates provide most of the energy needed in our daily lives, both for normal body functions such as heart- beat, breathing and digestion and for physical activity and exercise.

Which foods contain carbohyrates?
• Grains and grain products
• Fruits
• Vegetables
• Beans and legumes
• Dairy products
• Sugars

Do I need carbs?
High-carbohydrate foods are the best and sometimes only food sources of many essential nutrients, including:
• Fiber
• Vitamins C & E
• The majority of B vitamins
• Carotenoids and other beneficial phytochemicals
• Potassium
• The majority of trace minerals

A diet that is low in or deficient in any of these nutrients leads to many health problems, including increased risk for osteoporosis, high blood pres- sure and heart disease.

Are high-carbohydrate diets fattening?
Not necessarily. Obesity is uncommon in Asia where most people eat a very-high-carbohydrate diet. But not all high-carbohydrate foods are created equal. Some, such as whole grains, potatoes, fruits and vegetables, actually help you eat fewer calories without hunger.


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