calorie Balance: food and Beverage intake
Controlling calorie intake from foods and beverages is fundamental to achieving and attaining calorie balance. Understanding calorie needs, knowing food sources of calories, and recognizing associations between foods and beverages and higher or lower body weight are all important concepts when building an eating pattern that promotes calorie balance and weight management. Many Americans are unaware of how many calories they need each day or the calorie content of foods and beverages.
understanding calorie needs
The total number of calories a person needs each day varies depending on a number of factors, including the person’s age, gender, height, weight, and level of physical activity. In addition, a desire to lose, maintain, or gain weight affects how many calories should be consumed. Estimates range from 1,600 to 2,400 calories per day for adult women and 2,000 to 3,000 calories per day for adult men, depending on age and physical activity level. Within each age and gender category, the low end of the range is for sedentary individuals; the high end of the range is for active individuals. Due to reductions in basal metabolic rate that occurs with aging, calorie needs generally decrease for adults as they age. Estimated needs for young children range from 1,000 to 2,000 calories per day, and the range for older children and adolescents varies substantially from 1,400 to 3,200 calories per day, with boys generally having higher calorie needs than girls.
Knowing one’s daily calorie needs may be a useful reference point for determining whether the calories that a person eats and drinks are appropriate in relation to the number of calories needed each day. The best way for people to assess whether they are eating the appropriate number of calories is to monitor body weight and adjust calorie intake and participation in physical activity based on changes in weight over time. A calorie deficit of 500 calories or more per day is a common initial goal for weight loss for adults. However, maintaining a smaller deficit can have a meaningful influence on body weight over time. The effect of a calorie deficit on weight does not depend on how the deficit is produced—by reducing calorie intake, increasing expenditure, or both. Yet, in research studies, a greater proportion of the calorie deficit is often due to decreasing calorie intake with a relatively smaller fraction due to increased physical activity.
carbohydrate, protein, fat, and alcohol
Carbohydrate, protein, and fat are the main sources of calories in the diet. Most foods and beverages contain combinations of these macronutrients in varying amounts. Alcohol also is a source of calories.
Carbohydrates provide 4 calories per gram and are the primary source of calories for most Americans. Carbohydrates are classified as simple, including sugars, or complex, including starches and fibers. Some sugars are found naturally in foods (such as lactose in milk and fructose in fruit), whereas others are added to foods (such as table sugar added to coffee and high fructose corn syrup in sugar-sweetened beverages). Similarly, fiber can be naturally occurring in foods (such as in beans and whole grains) or added to foods. Most carbohydrate is consumed in the form of starches, which are found in foods such as grains, potatoes, and other starchy vegetables. A common source of starch in the American diet is refined grains. Starches also may be added to foods to thicken or stabilize them. Added sugars and added starches generally provide calories but few essential nutrients. Although most people consume an adequate amount of total carbohydrates, many people consume too much added sugar and refined grain and not enough fiber.
Protein also provides 4 calories per gram. In addition to calories, protein provides amino acids that assist in building and preserving body muscle and tissues. Protein is found in a wide variety of animal and plant foods. Animal-based protein foods include seafood, meat, poultry, eggs, and milk and milk products. Plant sources of protein include beans and peas, nuts, seeds, and soy products. Inadequate protein intake in the United States is rare.
Fats provide more calories per gram than any other calorie source—9 calories per gram. Types of fat include saturated, trans, monounsaturated, and polyunsaturated fatty acids. Some fat is found naturally in foods, and fat is often added to foods during preparation. Similar to protein, inadequate intake of total fat is not a common concern in the United States. Most Americans consume too much saturated and trans fatty acids and not enough unsaturated fatty acids. Alcoholic beverages are a source of calories but provide few nutrients. Alcohol is a top calorie contributor in the diets of many American adults.
Alcohol contributes 7 calories per gram, and the number of calories in an alcoholic beverage varies widely depending on the type of beverage consumed.