Empty calories

In human nutrition, the term empty calories applies to food such as solid fats or added sugars supplying food energy but little or no other nutrition. The USDA advises, "A small amount of empty calories is okay, but most people eat far more than is healthy."

The phrase is derived from nutrient density (proportion of nutrients in a food relative to its energy content), and calorie density (amount of energy relative to weight of the food). Thus empty calories are accompanied by no or few nutrients. Foods containing empty calories typically contain processed carbohydrates and ethanol (alcohol), and to some extent fats. Also known as a discretionary calorie, an empty calorie has the same energy content as any other calorie but lacks many accompanying nutrients such as vitamins, dietary minerals, antioxidants, amino acids, or dietary fiber. Although carbohydrates and fats are nutrients, they are typically ignored for this analysis, with the exception of essential fatty acids.

The error of considering energy foods as adequate nutrition was demonstrated by François Magendie by experiments on dogs and described in his Précis élementaire de Physiologie (1816). A book on sugar described the problem with empty calories as follows:

The following foods are often considered to contain mostly empty calories and may lead to weight gain:

All people require certain essential nutrients, but food energy intake must be balanced with activity to maintain a proper body weight. People who engage in heavy physical activity need food energy as fuel, which can be supplied by empty calories in addition to foods with essential nutrients. Sedentary individuals and those eating less to lose weight may suffer malnutrition if they eat food supplying empty calories but not enough nutrients.Dietitians and nutritionists prevent or treat illnesses by designing eating programs and recommending dietary modifications according to patient's needs. Eating a variety of nutritious foods every day protects against chronic illness and helps to maintain a healthy immune system.

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