This article seems to be based on a mistaken premise. There is nothing wrong with the calorie as a unit of measurement. The problem is an inability to accuratel

This article seems to be based on a mistaken premise. There is nothing wrong with the calorie as a unit of measurement. The problem is an inability to accurately measure it. There is simply not a good way to measure human calorie expenditure. Fitbits and their ilk are, to put it bluntly, useless. They measure the number of movements, not the work expended for each movement. They cannot distinguish between a step taken on flat ground or an incline (or decline) or even the difference between an arm movement and a body movement. It wouldn't be impossible to measure total calorie expenditure, but it would be pretty impractical. You'd basically need to isolate the person from the external environment and measure the total heat produced by that person's body. But, like other commenters have pointed out, you don't even need to measure calorie expenditure to lose weight. You just need a running average of calorie intake and of weight loss. If weight loss is too low or too high, adjust your calorie intake and wait for more data. Repeat as needed.