A male worker consumes food containing a total of 3500 calories (3500 kcal) each day. He is 60 years old and weighs 200 lb. He sleeps 8 hr each night, and his average energy expenditure rate while sleeping is assumed to be his basal metabolic rate. When he is not working or sleeping, his energy expenditure rate averages 1.7 kcal/min (no correction for weight). What must be his average energy expenditure rate (kcal/min) for the 8 hr he works, if it is perfectly balanced with his food calorie intake? His digestive metabolism is assumed to be 10% of the total of his basal and activity metabolic rates over 24 hr.