Protein is one of the three macronutrients found in food, alongside carbohydrates and fats. While fat provides 9 calories per gram, carbohydrates and protein provides 4 calories per gram. This means that for every gram of protein consumed, it contributes approximately 4 calories to the total energy content of the food.

To calculate the calorie content of a food item that contains protein, you need to know the amount of protein it contains. This information is typically found on nutrition labels or in nutritional databases.

Here's an example: If a food item contains 20 grams of protein, you can calculate the calorie content from protein by multiplying the protein amount by 4:

Calories from protein = 20 grams * 4 calories/gram = 80 calories

Therefore, in this example, the food item would contribute 80 calories to your overall energy intake from protein.

It's worth mentioning that while protein provides calories, its primary role is not energy production but rather as a building block for various tissues in the body, such as muscles, enzymes, and hormones. The Dietary Reference Intake (DRI) recommends that protein intake be based on individual factors such as age, sex, weight, activity level, and overall health goals.

The Dietary Reference Intake (DRI) for protein is the amount of protein intake recommended by health authorities to meet the nutritional needs of most healthy individuals. The DRI for protein varies depending on age, sex, weight, activity level, and other factors. Here are the general DRI recommendations for protein:

1. Infants:

   • 0-6 months: 9 grams per day

   • 7-12 months: 11 grams per day

2. Children:

   • 1-3 years: 13 grams per day

   • 4-8 years: 19 grams per day

   • 9-13 years: 34 grams per day

3. Adolescents:

   • Boys 14-18 years: 52 grams per day

   • Girls 14-18 years: 46 grams per day

4. Adults:

   • Men 19 years and older: 56 grams per day

   • Women 19 years and older: 46 grams per day

It's important to note that these values represent the Recommended Dietary Allowance (RDA) for protein, the average daily intake sufficient to meet the nutrient requirements of nearly all healthy individuals in a particular life stage and sex group. However, individual protein needs may vary based on activity level, muscle mass, health conditions, and specific goals (e.g., athletes may require higher protein intake for muscle building or recovery).

Additionally, it's worth mentioning that the DRI values are general guidelines and personalized recommendations from healthcare professionals or registered dietitians may be necessary for individuals with specific dietary needs or medical conditions.

Lastly, it's important to obtain protein from various sources, such as lean meats, poultry, fish, dairy products, legumes, nuts, and seeds, to ensure a balanced intake of essential amino acids and other nutrients. MyPlate recommends filling 1/4th of the plate with varied and heart-healthy protein. Heart healthy means low in saturated fat.

The United States Department of Agriculture (USDA) conducts periodic surveys to assess the average American population's dietary patterns and nutrient intake. The most recent comprehensive survey conducted by the USDA is the National Health and Nutrition Examination Survey (NHANES), which collects data on various aspects of health and nutrition, including protein consumption.

According to the NHANES data from 2015-2016, the average protein intake for Americans aged two years and older was approximately 98 grams daily. It's important to note that this value represents an average and may vary based on individual factors such as age, sex, activity level, and dietary preferences.

The USDA's recommended daily protein intake for adults is around 46 grams for women and 56 grams for men. Therefore, based on the NHANES data, the average protein consumption of the American population appears to meet or exceed the recommended levels.

The Dietary Guidelines for Americans 2020-2025, developed by the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS), provide evidence-based recommendations for a healthy diet. Here are the key points regarding protein intake from the current guidelines:

1. Recommended Daily Amount: The guidelines recommend a range for protein intake, expressed as a percentage of daily calorie intake. The range is 10% to 35% of total daily calories. The specific protein needs within this range can vary depending on factors such as age, sex, and activity level.

2. Age-Specific Recommendations:

   • Infants and Young Children: For infants aged 0-6 months, the guidelines recommend that breast milk or infant formula should be the sole source of nutrition. For infants aged 6-12 months, complementary foods should be introduced to meet energy and nutrient needs, including protein.

   • Children and Adolescents: The guidelines recommend age-appropriate protein intake for children and adolescents to support growth and development. The specific protein requirements increase as children get older.

   • Adults: The guidelines state that adults should aim to meet their protein needs while staying within the recommended range of 10% to 35% of total daily calories. Protein intake can come from a variety of sources, including animal and plant-based foods.

3. Variety of Protein Sources: The guidelines emphasize the importance of consuming a variety of protein foods, including seafood, lean meats, poultry, eggs, legumes, nuts, seeds, and soy products. This variety helps to ensure intake of essential nutrients and different types of protein.

4. Nutrient-Dense Choices: The guidelines encourage choosing protein foods that are nutrient-dense and lower in saturated fats, added sugars, and sodium. This includes lean meats, poultry without skin, seafood, eggs, nuts, seeds, legumes, and low-fat or fat-free dairy products.

5. Consider Sustainability: The dietary guidelines also acknowledge the importance of considering the environmental impact of food choices. They suggest choosing protein sources that are produced sustainably, such as seafood, plant-based proteins, and lean meats from animals raised using sustainable practices.