Calculation of calories by different methods

                  In general, water is not considered as a food, Calorie need. This must be satisfied. In an adult healthy man the calorie Intake = the calorie expenditure. Again, the calorie expenditure = BMR + extra calories expended during various works.  BMR in a healthy adult person can be calculated, as BMR is 40K cal or 37 K cal, per s q m per hour in males and females respectively. Most of them are applicable for a homogeneous community living, in, say, military or police barracks.  Their work loads, ambient temp, etc. being known, the total calories can be calculated and from them, the extra calories needed per head can be found out. Another method is to compare with a so called ‘reference man’. For example, a hypothetical man has been imagined who represents the ‘average’ in an ‘average’  ambient temperature.  The parameters of the particular person, whose diet is going to be formulated, can be compared with the reference man, that is, his body surface area,  ambient temp.One of the most universally applied practical method for the masses is to keep a weight chart of the person concerned.  The person (who is, say, healthy adult) is allowed to eat as much as he likes (i.e. ‘his appetite governs the amount of food’). Subsequently if he begins to develop obesity, the  calories are cut down.Or if there is loss of body weight, calories are added. However, in case of growing children this should lead  to normal  growth. In this connection, it is important to have a gross idea about the calorie requirement at the beginning.  Heavy manual workers (wood  choppers, earth diggers, rickshaw pullers, sportsmen undergoing training for the tournament) for every hour of their heavy muscular work, expend around 570 K cal/hr (=2,400 K/hr) or more.  Values for light and moderate works are also available. Examples of light works are shaving, dressing and light domestic works.  Examples of moderate works are walking at brisk pace, soil tilling in agriculture and so on. On  an  ‘average’moderately working healthy adult male requires about 2200 Kcal/day.  Excess intake of calories will lead to as stated earlier,  obesity,  whereas the reverse produces starvation.