By William Cabot, M.D., FAAOS
We all crave more energy. It is disheartening to start the day feeling tired before you go to work or try to work up the impetus to go to the gym.
Our lives are intruded upon by both physical and emotional obstacles. Taking a personal inventory of our experiences clearly shows that when we have more physical and spiritual energy the unpleasant intrusions of life are easier to deal with.
Energy has psychological and nutritional components. They are both important. In this article I will address the nutritional aspect of various foods that have the ability to impact our energy levels. Time and space does not permit a discussion of everything. This article will hopefully provide motivation to explore more on your own.
HOW DO WE MEASURE ENERGY DERIVED FROM FOOD?
Foods are divided into three main groups: proteins, carbohydrates, and fats (lipids). All energy yielding nutrients fall into one of these categories (1).
We measure energy by a term that is familiar to all of us…calories. One calorie is the amount of energy required to raise the temperature of one gram of water by 1 degree centigrade (2). It is the most common method to describe energy generated by food intake.
ENERGY GENERATED BY PROTEINS, FATS, AND CARBOHYDRATES
These are the three principle food categories. They do not all generate the same amount of energy when digested and used by the body as a source of fuel. Proteins and carbohydrates each generate 4 calories per gram. Fat (lipids) generates 9 calories per gram (2).
Fats generate over twice as much energy as proteins or carbohydrates. A diet which is skewed too much in favor of very high fat content generates a lot of energy but at the expense of an expanding waistline and negative cardiovascular effects.
A high fat diet is not recommended from a health standpoint. There are many other food products that will generate energy without the negative consequences of indulging in a diet which may cause you to be at an increased risk for coronary artery disease.
The Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg/ (or 2.2 lbs.) (3). This works out to approximately 58 to 63 grams per day for an average adult male.
In addition to producing a reliable source of energy, protein has the added benefit of superior satiety. Satiety is a feeling or condition of being full after eating food. It is the state of no longer being hungry.
High protein diets were compared with high carbohydrate diets. Diets which were higher in protein and lower in carbohydrate were found to decrease an individual’s total caloric intake. They were well tolerated and resulted in increased energy expenditure compared to standard high-carbohydrate diets (4, 5 ).
There are a multitude of protein sources for one to choose available at the grocery. For those people who are vegetarians soy and quinoa provide extremely high quality complete protein sources in new and appetizing forms (6).
Complex carbohydrates are made up of sugar molecules that are strung together in long, complex chains. Simple carbohydrates on the other hand are composed of just a few sugar molecules which are very easily digested and provide the quickest source of energy (7).
Unfortunately, the energy burst produced by simple carbohydrates is frequently followed by a lack of energy. This occurs because these diets cause the rapid release of the hormone insulin which in turn causes blood glucose levels to drop resulting in a feeling of fatigue and no energy.
Complex carbohydrates are typically found in foods that have starches or fibers. They take much longer to digest therefore providing a longer lasting source of energy. Both simple and complex carbohydrates are metabolized to glucose (blood sugar) in the body and are used as energy.
Examples of simple carbohydrates are granulated sugar, corn syrup, honey, jams and jellies, candy, and soft drinks. These should be avoided if you are looking for more than just a burst of energy. Complex carbohydrates can be found in whole grains, pasta, and starchy vegetables such as sweet potatoes and pumpkin, lentils and peas, among others. These foods will maintain an increased energy level for a more prolonged period of time.
KNOWN ENERGY PRODUCERS
As you know there are many foods we could highlight. We want to focus on a few that are known energy producers.
Bananas have actually been found to be a fabulous energy producer during exercise (8). They are rich in potassium and vitamin B, and actually have the effect of decelerating digestion. This keeps blood sugar levels stable and enables you to have that full feeling for a longer period of time.
Studies done on cyclists found that bananas were equivalent to chocolate in producing long lasting energy (8). This is why you see so many professional athletes ingesting them at events such as tennis matches.
There are several reasons that nuts have the ability to provide energy (9, 10). Nuts have a high fat content. The fat content however is weighted in the form of the beneficial unsaturated as opposed to the saturated type of fat.
There are additional beneficial attributes nuts have that make them a great source of both nutrition and energy. They contain bioactive entities such as fiber, vitamins, and antioxidants, all of which have a positive biological effect. Nuts are high in magnesium which is an essential mineral proven to enhance exercise performance (9, 10).
Lean beef, chicken, turkey, and pork all have the ability to increase your energy levels. In addition to being good sources of protein, they have high levels of the amino acid Tyrosine. This amino acid has the ability to reduce stress (11).
Unfortunately, stress is very much a part of many lives, both at work and at home. Too much stress can easily lead to decreased energy, exhaustion, and depression. The amino acid Tyrosine is a chemical precursor of the neurotransmitters in the brain called dopamine and norepinephrine. Tyrosine is also necessary for the proper functioning of your adrenal, thyroid, and pituitary glands.
It is also important to include one more element that is essential in this discussion….water. One cannot overemphasize the importance of proper hydration for the maintenance of good health. Both cognitive function and metabolic processes needed to maintain the body in homeostasis require adequate hydration (10, 11).
The complex functions that go on within our cells including the production of energy and proteins to sustain life all require water. Exercise and workplace performance can be negatively impacted by less than adequate hydration (12).
Exactly how much water we each need is a debated topic. The Mayo Clinic recommends 3.7 liters per day for men and 2.7 liters per day for women. 20% of that is in the food that we eat (12). Others in the scientific community have challenged the premise that eight large glasses of water per day is mandatory for good health (13).
The main point is to stay well hydrated to effectively dissipate body heat and provide hydration for our molecular biological functions to proceed on a cellular level. This will result in increased energy to perform the activities of daily living.
The ability to work and enjoy leisure time activities is dependent on having an adequate level of energy. We don’t all have the same metabolism or enjoy the same level of physical or mental activity. Being conscientious about what we eat can help maintain a level of energy that allows us to pursue leisure time activities and be productive at work and the end result is a better quality of life.
1. Andersson A et al, Towards a healthy diet: from nutrition recommendations to dietary advice; Scand J Food Nutr. 2007 Mar, 51(1): 31-40.
2. Grodner M et al; Nutritional foundations and clinical applications, 5th ed; Elsevier Mosby 2012:8-11.
3. Otten JJ, et al, editors: Dietary DRI References: The essential guide to nutrient requirements, Washington, DC, 2006, The National Academies Press.
4. Halton TL et al; The effects of high protein diets on thermogenesis, satiety, and weight loss: a critical review: J Am Coll Nutr. 2004 Oct;23(5):375-85.
5. Gillingham MB et al; Effects of higher dietary protein intake in energy balance and metabolic control in children with long chain 3-hydroxyl acyl-CoA dehydrogenase (LCHAD) or trifunctional protein (TFP) deficiency. Mol Genet Metab 2007 Jan;90(1):64.
7. Ferretti F et al; Simple vs. complex carbohydrate dietary patterns and the global overweight and obesity epidemic:Int J Environ Res Public Health. 2017 Oct 14 (10):1174.
8. Nieman DC et al; Bananas as an energy source during exercise Plos One 2012;7(5)::e37479. Published online 2012 May 17.
9. Brufau G et al; Nuts:source of energy and macronutrients; Br J Nutr 2006 Nov;96 Suppl 2:S24-8.
10. Zhang Y et al; Can magnesium enhance exercise performance?;Nutrients 2017 Sep;9(9):946.
11. Young SN: L-Tyrosine to alleviate the effects of stress?:J Psychiatry Neurosci. 2007 May;32(3):224.
13. VAltin H; “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8X8”?; Am J Regul Integr Physilo. 2002Nov;283(5):R993-1004.