Changes

==Roles in the Body==

==Roles in the Body==

'''Energy expenditure and requirement for intake is dependent on the '''Basal Metabolic Rate''' ('''BMR''', the energy required for normal physiologic functions in a fasted, thermoneutral environment); activity level (normal physical activity and exercise); dietary thermogenesis (energy used during digestion and assimilation of food); and adaptive thermogenesis (energy needed to maintain body temperature in cold environments)'''. In a thermoneutral environment BMR accounts for approximately 60% of the animal’s total daily energy expenditure, while normal activity is 30%, and dietary thermogenesis accounts for 10% energy utilization<ref>Case LP, et al. In Canine and Feline Nutrition: A resource for Companion Animal Professionals. 2011 Third Ed. St. Louis: Mosby p.59-61.</ref>. Energy expenditure for adaptive thermogenesis varies with temperature, humidity and coat thickness<ref>National Research Council (NRC). Physical Activity and Environment. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p.267-273.</ref>.

Energy expenditure and requirement for intake is dependent on:

* '''Basal Metabolic Rate''' ('''BMR''') - the energy required for normal physiologic functions in a fasted, thermoneutral environment

* '''activity level''' - normal physical activity and exercise

* '''dietary thermogenesis''' - energy used during digestion and assimilation of food

* '''adaptive thermogenesis''' - energy needed to maintain body temperature in cold environments

 

In a thermoneutral environment, BMR accounts for approximately 60% of the animal’s total daily energy expenditure, while normal activity is 30%, and dietary thermogenesis accounts for 10% energy utilization<ref>Case LP, et al. In Canine and Feline Nutrition: A resource for Companion Animal Professionals. 2011 Third Ed. St. Louis: Mosby p.59-61.</ref>. Energy expenditure for adaptive thermogenesis varies with temperature, humidity and coat thickness<ref>National Research Council (NRC). Physical Activity and Environment. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p.267-273.</ref>.

'''Resting energy requirement (RER)''' accounts for both BMR and dietary thermogenegisis. RER is determined by lean body mass, but may vary with age, breed, gender, neuter status, and the presence of disease. For both dogs and cats, RER can be calculated using exponential equations based on body weight using ('''70*BWkg0.75''')<ref>Klieber M. The fire of life. 1961 New York: John Wiley & sons.</ref>. '''A number of factors can influence daily energy requirements, such as breed, reproductive or neuter status, activity level (e.g., sedentary vs. working dog), and environment (e.g., indoor vs. outdoor, kennel/cattery vs. a home)''' and relying on published maintenance energy requirement (MER) equations can be problematic if these variants are not account for.  

'''Resting energy requirement (RER)''' accounts for both BMR and dietary thermogenegisis. RER is determined by lean body mass, but may vary with age, breed, gender, neuter status, and the presence of disease. For both dogs and cats, RER can be calculated using exponential equations based on body weight using ('''70*BWkg0.75''')<ref>Klieber M. The fire of life. 1961 New York: John Wiley & sons.</ref>. '''A number of factors can influence daily energy requirements, such as breed, reproductive or neuter status, activity level (e.g., sedentary vs. working dog), and environment (e.g., indoor vs. outdoor, kennel/cattery vs. a home)''' and relying on published maintenance energy requirement (MER) equations can be problematic if these variants are not account for.