19 3.3 Energy Requirements and Dietary Health
Energy Derived from Nutrients
Nutrients in food provide an individual with energy input (energy derived from consumption), and fuel energy expenditure (energy which is utilized to maintain bodily functions and physical activity) (Williams, 1999).
Calorie: A unit of energy in food. In nutrition, the true unit of measure is a kilocalorie (kcal), but is often referred to simply as a “calorie” (Williams, 1999). Note: When referring to a Calorie as a measure of heat, the correct definition is, “The energy required to raise the temperature of 1 gram of water 1 degree Celsius.”
The majority of energy (i.e., calories) contained in food (i.e., carbohydrates, proteins, fats) is absorbed into the body during digestion. The caloric value of 1 gram carbohydrate, protein, fat, and alcohol are listed, below. Minerals and vitamins do not provide a measurable source of energy for the body (Williams, 1999).
1 gram carbohydrate = 4 calories (kcal)
1 gram protein = 4 calories (kcal)
1 gram fat = 9 calories (kcal)
1 gram alcohol = 7 calories (kcal)
Consider your current diet and the aforementioned caloric values for macronutrients and alcohol. Where do you believe most of your caloric intake is coming from?
Note: The EER activity provides a general estimate of how energy-intake needs may change based upon physical activity level and is NOT intended as a diet plan; dietary recommendations may only be made by a licensed healthcare professional.
Choosing Nutrient-Dense Foods
A nutrient-dense food is one that is high in nutrients, but comparatively low in calories. Nutrient-dense foods contain micronutrients (vitamins and minerals) and macronutrients (complex carbohydrates, protein, and healthy fats).
Common Nutrient-Dense Foods: Fruits and vegetables, whole grains, low-fat or fat-free milk products, seafood, lean meats, eggs, peas, beans, and nuts.
The human body needs essential nutrients in order to function. Consuming a variety of nutrient-dense foods in your weekly diet is a simple strategy to ensure that you are getting the needed macronutrients and micronutrients for optimal health and wellness. Can you list at least 35 different nutrient-dense foods you consume in one week? If not, please take a moment to expand upon your weekly food list.
Nutrition and Reduction of Risk for Chronic Disease
An individual’s diet may reduce the risk for certain conditions or diseases. Current literature suggests that dietary factors may play a role in the development of several chronic diseases, including but not limited to the following: diabetes, cardiovascular disease, and cancer (Fardet & Boirie, 2014). The World Health Organization (WHO) has identified several harmful health outcomes which may be meaningfully influenced by diet: excess weight and obesity, low bone mineral density and osteoporosis, and poor dental health (Nishida, Uauy, Kumanyika, & Shetty, 2004). Recent research has focused upon an association between increased consumption of fruits and vegetables, and reductions in the risk for all-cause mortality and cardiovascular mortality.Specific nutrients may combat harmful health conditions when they interact with metabolic processes. Metabolic pathways include the inactivation of carcinogens, reductions in inflammation, body fat, and insulin sensitivity, and improvements in the immune system (Williams, 1999). Recent research has focused upon an association between increased consumption of fruits and vegetables, and reductions in the risk for all-cause mortality and cardiovascular mortality (Wang, et al., 2014). However, the literature regarding potential correlations between diet, disease, and risk reduction is vast, and therefore will not be explored in great detail within the confines of this chapter. Rather, recommendations for interpreting the current dietary guidelines and developing healthy dietary behaviors will be discussed in upcoming sections of Chapter 3.
Fardet, A., & Boirie, Y. (2014). Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews. Nutrition reviews, 72(12), 741-762.
Nishida, C., Uauy, R., Kumanyika, S., & Shetty, P. (2004). The joint WHO/FAO expert consultation on diet, nutrition and the prevention of chronic diseases: process, product and policy implications. Public health nutrition, 7(1a), 245-250.
Wang, X., Ouyang, Y., Liu, J., Zhu, M., Zhao, G., Bao, W., & Hu, F. B. (2014). Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. Bmj, 349, g4490.
Williams, M. H. (1999). Nutrition for health, fitness and sport (No. Ed. 5). WCB/McGraw-Hill.