Energy balance and its regulation
This chapter considers the physiological mechanisms that regulate energy intake. Regulation of energy balance could be achieved by regulation of energy intake or expenditure or by a combination of the two. Traditionally, therefore, studies on the regulation of energy balance have focused upon the mechanisms regulating food intake. The lateral and ventromedial areas of the hypothalamus are considered to play important roles in feeding regulation. Details of the location of the various hypothalamic regions including likely pathways involved in the control of several important functions including thermoregulation and food intake can be found in C. B. Saper and B. B. Lowell. Some apparent increase in “metabolic efficiency” occurs during fasting and food restriction; Basal metabolic rate falls during fasting even after correction for any decrease in lean body mass. When deprived of food, one of the ways that even normal mice can respond is to become torpid i.e. they slow metabolism and decrease their core body temperature.