Willpower

Willpower is the ability to resist an impulse in order to reach a goal – and it's one of the least reliable forces you can count on when losing weight. In the evening, tired, hungry, after an argument: exactly when you'd need it, it's at its weakest. That's not a question of character but of biology. A stressed, sleep-deprived brain reaches for quick comfort.

For a long time, willpower was thought of as a muscle that gets tired: in 1998, the psychologist Roy Baumeister reported that people gave up more quickly on a second task after a strenuous self-control task. However, a large replication study involving 23 labs failed to find this effect in 2016 – just how exhaustible willpower really is remains under debate. Something else is well established: people with high self-control need to use it less often in everyday life. Studies, including some from the team of psychologist Angela Duckworth, show that they tend to build habits and avoid temptations rather than constantly resisting them.

The famous marshmallow test by Walter Mischel is also often misunderstood: the children who were able to wait didn't grit their teeth – they distracted themselves, sang, covered their eyes. A larger follow-up study (2018) also found that the link with later academic success is much smaller than thought and depends to a large extent on background and environment. The lesson: don't try to get stronger – shape your surroundings more cleverly.

In practice, this means: what you don't want to eat doesn't come into the house, or goes in the top cupboard. What you do want to eat is visible and ready-cut in the fridge. Decisions move to calm moments – weekly plan, shopping list, if-then plan. Sleep and regular meals keep the tank full. And for families: don't put children to the test. A bowl of sweets on the table doesn't test willpower, it challenges it constantly – for children and parents alike.