|Nutrient Key Information|
|Nutrient Category:||Macronutrients (Proximates)|
|Nutrient Summary:||Energy is required to sustain the body’s various functions, including respiration, circulation, nerve transmission, physical work, metabolism, and protein synthesis.|
Sample Foods High in: Energy
|Food Description||Nutrient Amount1||Daily Value%2|
Bread, whole-wheat, commercially prepared
Category: Baked Products
Rice, white, medium-grain, enriched, cooked
Category: Cereal Grains and Pasta
Oil, olive, salad or cooking
Category: Fats and Oils
Nuts, almonds, dry roasted, with salt added
Category: Nut and Seed Products
Beef, round, bottom round, steak, separable lean and fat, trimmed to 1/8" fat, all grades, cooked, braised
Category: Beef Products
Fish, tuna, fresh, bluefin, cooked, dry heat
Category: Finfish and Shellfish Products
|Nutrient Detail Information|
|Nutrient Summary||Energy is required to sustain the body’s various functions, including respiration, circulation, nerve transmission, physical work, metabolism, and protein synthesis.|
Energy is supplied by carbohydrates, proteins, and fats in the diet. They are generally referred to as macronutrients. The general Calories Calculation Formula is:
Carbohydrate-gram x 4 + Protein-gram x 4 + Fat-gram x 9
Expert recommended calories range for each source is:
Total Fat: 20-35%
In a human body, energy is presented in the forms of:
• Heat energy: such as keeping body in the constant temperature
• Mechanical energy: such as moving muscles
• Electrical energy: such as transmitting nerve signals
• Chemical energy: such as performing anabolic reactions to build larger compounds from smaller molecules
Carbohydrate, Fat, and Protein generate compounds called acetyl CoA during their metabolism process. Acetyl CoA is used to generate energy compound ATP (Adenosine TriPhosphate) for immediate energy use. If the body has enough ATPs, the excessive acetyl CoA is converted into body fat as energy storage used later.
A person's energy intake requirements and expenditure depend on this person's age, body composition, gender, and physical activity level. The Estimated Energy Requirement (EER) is defined as the average dietary energy intake required to maintain the energy balance of the body to maintain health. It reflects the average needs for general people with specific characteristics, such as age, gender, weight, height, and a level of physical activity.
Energy Measuring Unit:
The measuring unit of energy is kcal (kilocalorie or Calorie in upper case C, also called large calorie). 1 kcal is the amount of energy required to raise the temperature of 1 kg water by 1°C (one degree Celsius). United States and Canada food nutrition labels use "Calories" to refer to kilocalorie. Another measuring unit of energy is kilojoule (kJ). 1 kcal = 4.184 KJ. Europe and China food nutrition labels usually use KJ.
Fasting or Starving:
When a person is fasting or starving, the body draws reserved glycogen (mainly in liver, and it is for glucose) and fat (in adipose tissue) from body storage to provide glucose, glycerol, and fatty acids for energy. When use up body glycogen (in about 24 hours) or use up fat, body will break down protein tissues (such as muscle) to generate glucose and other energy source to fuel body cells. Protein tissues are vital to living bodies, you don't want to use them as the main energy source.
During fasting, the biggest challenge is the limited availability of glucose which is required for brain, nerve system, and red blood cells to function properly. Fatty acids in the fat tissues cannot convert to glucose. For emergent needs, liver can convert fats to ketone bodies to fuel brain (but it can cause side effects).
Top Food Sources
Carbohydrate, Fat, and Protein are the sources of energy.
Most of cells can use glucose or fatty acids as fuel. However, brain and central nervous system and red blood cells must have glucose as fuel. Brain and nervous system use about 500 kilocalories glucose per day. Carbohydrate is the primary source for glucose, and protein is the secondary source for glucose.
Implication of excessive intake of the 3 energy food sources:
In summary, we must have balanced diets for Carbohydrate, Fat, and Protein.
|Deficiency Health Effects||If energy intake is lower than energy needs, the body adapts by reducing voluntary physical activity, reducing growth rates for children, and mobilizing energy reserves. It will lead to weight loss. For children, chronic undernutrition will cause slow growth weight, delayed bone growth, and impact brain development. For adult, it will decrease work capacity. Learn more in the Fasting paragraph of the Nutrient Function section.|
|Effects if Above Upper Limit||If energy intake is higher than energy needs, the excess energy cannot be eliminated and they will be deposited in the form of body fat. As a result, weight gain occurs. It consequently increases chronic disease risk, including risk of Type II diabetes, hypertension, coronary heart disease (CHD), stroke, gallbladder disease, osteoarthritis, and some types of cancer.|
Measuring Unit for Energy:
- One kilocalorie (kcal): the amount of heat energy needed to raise the temperature of 1 kilogram (kg) of water 1°C.
- International unit One Joule: the amount of work energy that moves a mass 1 meter distance using 1 newton force.
1 kilocalorie (kcal) = 4.184 kilojoules (KJ, 1000 Joule)
|Daily Value Age Group||Recommended Daily Values|
|Toddler 1 to 3 years old:||1,000 kcal|
|Child 4 to 8 years old:||1,400 kcal|
|Male 9 to 13 years old:||1,800 kcal|
|Male 14 to 18 years old:||2,600 kcal|
|Male 19 to 30 years old:||2,800 kcal|
|Male 31 to 50 years old:||2,600 kcal|
|Male 51 to 70 years old:||2,400 kcal|
|Male Senior 71 or older:||2,200 kcal|
|Female 9 to 13 years old:||1,800 kcal|
|Female 14 to 18 years old:||2,000 kcal|
|Female 19 to 30 years old:||2,200 kcal|
|Female 31 to 50 years old:||2,000 kcal|
|Female 51 to 70 years old:||1,800 kcal|
|Female Senior 71 or older:||1,800 kcal|
|Female Pregnancy (>18):||2,200 kcal|
|Female Lactation (>18):||2,200 kcal|
|FDA (Based on 2000 calorie daily diet):||2,000 kcal|
|The nutrient Dietary Reference Intakes and nutrition facts is from Institute of Medicine of National Academies 2006. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: The National Academies Press. https://doi.org/10.17226/11537|
|Nutrition facts knowledge are based on U.S. FOOD & DRUG Administration Nutrition Education Resources & Materials. https://www.accessdata.fda.gov/scripts/interactivenutritionfactslabel/|
|Nutrition facts knowledge are based on National Institutes of Health Dietary Supplement Fact Sheets. https://ods.od.nih.gov/factsheets/list-all|
|Disclaimer||The nutrient information provided here should not take the place of medical advice. We encourage you to talk to your healthcare providers (such as your doctor) about your dietary requirements which are best for your overall health. We also recommend you to read organization or professional reference documents or articles mentioned, but not limited to, in this page. Any mentions and reference links in this page don't represent our endorsement of their services and advice.|