A lack of willpower may seem frustrating, but it is crucial to human evolution, scientists believe, proving people should not despair too much about their slip-ups.
Dr Ian Taylor, a psychologist and expert in human motivation from Loughborough University, claims a breech of willpower allowed for our ancestors to explore unchartered avenues and seek new experiences.
Speaking at the Cheltenham Science Festival, Taylor said: "Willpower can be thought of as the ability to override, to resist the temptation in favour of valued goals.
"Most people think that willpower is amazing. But you don't want to rely on it. If you are relying on willpower then there is going to be problems.
"When you need to use willpower it doesn't feel very nice. It's fragile, it will break.
Evolutionarily speaking, it is good for it to break. When willpower breaks you explore different things, so our ancestors wouldn't want to keep using the same habitats, using the same food stores, using the same mates."
Taylor argued that to resist temptation, people should not focus on the thing they were trying to avoid, but rather identify with the person they hope to become.
A person on a diet should not think of themselves as a "dieter" but rather a healthy eater, for instance.
"Nobody wants to be associated with a negative identity," he added. "If you are trying to do something you can describe it to yourself as trying to trigger a positive identity."
- Telegraph Group Ltd