Lack of exercise
When we consume more calories than we burn, we gain weight: The math is that simple! If we don't move enough, we will not only burn fewer calories, but our muscles will also begin to shrink because we don't put demands on them. As the saying goes, "Use it or lose it!"
And this situation is fatal, because the less muscle we have, the less we can burn. The excess calories get stored directly in our fat cells!
Our ancestors walked about 20 kilometers (12 miles) a day to get food. And us? On average, the modern office worker walks just 600 meters (1/3 mile) a day. From the coffee machine to the car, into the elevator and to an office chair. A trip to the coffee machine or cafeteria ends up being one of the activity highlights of the day.
And what about your movement?