if ( calories in > calories used) then gain weight (store the excess for later as fat) if (calories in < calories used) then lose weight (burn fat previously s

if ( calories in > calories used) then gain weight (store the excess for later as fat) if (calories in < calories used) then lose weight (burn fat previously stored to keep running the machine) You can make that on a daily, monthly or yearly timescale, it makes no difference. Everything we know about physics says it is the only way.