The results of a survey showed that those with the most positive and optimistic attitudes had the greatest improvement in dietary structure during the duration of the study, while the most negative and pessimistic respondents not only preferred to choose a less healthy diet from the beginning, but also After intervention by various means, the improvement is not ideal. Researchers have pointed out that self-control is the key to making it easier for optimists to successfully quit bad habits such as smoking, drinking and overeating. What is the correct understanding of this text? ['The dietary structure depends on the mood of a person.', 'Unhealthy eating habits are difficult to improve with intervention.', 'Positive people are more likely to improve bad eating habits.', 'The self-control of the pitiful cannot be improved through intervention.']