How we praise one another or ourselves may be affected by whether we have an entity theory or incremental theory about personality traits such as intelligence, or other traits such as trustworthiness or fairness. Hearing praise about what a good child we are can leave the underlying impression that if circumstances were different then we would be a bad child. Praise about how good we were for scoring well on the test or for drawing a pretty picture may be leaving the impression that next time if we score poorly on the test or make a less nice drawing that we are a bad child. 
Praise that focuses on the effort involved – or lack of effort – instead focuses on the job at hand rather than any innate goodness or badness. Praise about the effort involved, such as, “Great, you finished almost all of the questions and put in a lot of work on solving them, with more time you may have been able to finish all of the problems,” might be more successful in the long run at promoting a sense that working hard on a problem can lead to success without placing an external judgement on the child’s general goodness or badness. Praising the process that a child used rather than praising or criticizing the child may help children feel more confident about their ability to successfully handle challenges. Praise feels good in the short term but can lead the child to be more self critical and to give up when they run into more difficult work. 
Research suggests that people with a more fixed view of personality, or entity theory, may be judging others and themselves more harshly. While people with the more fluid view of personality, the incremental theory that people can change and improve their skills over time, make fewer snap judgments about themselves or others. 
Within the field of nutrition people who are trying to practice healthier eating habits may face setbacks in their food choices. It is important for the overall success of the dietary changes for them to see the unhealthier choices as simply unhealthier choices for that day or meal rather than a more general reflection of their overall chances of sticking with the new eating habits over time. One day’s unhealthy choices are unlikely to lead to long term ill health but if the unhealthy choices are viewed as proof that the person is a bad person who might as well give up trying then the day’s unhealthy choices might add to the long term risk of ill health. Eating disorders can be a person’s way of trying to cope with unrecognized emotional issues. Gentleness with oneself while trying to practice new eating habits may help with getting through minor setbacks without giving up on the overall goal of change.
The book Self-theories; Their Role in Motivation, Personality, and Development, (1999), by Carol S. Dweck, is written for the academic field of social psychology however it is a review of research and doesn’t go into detail about statistical analysis which makes it fairly accessible for the general interest reader. It is part of the series Essays in Social Psychology by Psychology Press. 
Anorexia nervosa, an eating disorder characterized by severe control of caloric intake, is mentioned as an example of a condition where individuals can harm themselves in the pursuit of a perfect self (, page 138) but the book is not about nutrition specifically. It discusses how cognitive therapy techniques can help children and adults learn more productive views of self and how well meaning praise may actually be promoting increased risk of giving up when setbacks are encountered. How we talk to children and adolescents about their size can have significant impact on the risk of their developing disordered eating patterns:
A focus on healthy exercise habits and regular meals of various types of foods may be more helpful than overly focusing on weight or size or a few specific food choices. Health occurs over time not just at each meal. Process oriented help for healthy eating might better focus on helping the person recognize their hunger and fullness signals and recognizing when thirst for water might actually be the primary body sensation they are feeling.
The fixed or entity theory of self might suggest to a child or adult that their ability to change their eating habits or fitness level is not possible while a fluid incremental theory of self might suggest that with effort the child or adult’s ability to change their eating habits or fitness level is possible. It can be helpful to not make weight loss or size changes the primary goal when trying to help someone address eating habits. Changing habits can support a healthy gradual change in weight or size or may help reduce the risk of chronic diseases such as Type II diabetes or high blood pressure from developing even if there aren’t large changes in weight or size. Cognitive behavior therapy can be helpful for promoting healthy eating and lifestyle changes. [2, 3]
/Disclosure: I am a nutritionist. Disclaimer: Information presented on this site is not intended as a substitute for medical care and should not be considered as a substitute for medical advice, diagnosis or treatment by your physician. Please see a health professional for individualized health care services./
- Carol S. Dweck, Self-theories; Their Role in Motivation, Personality, and Development, (Psychology Press, 1999, Ann Arbor) 
- Denise E. Wilfley, Ph.D., Rachel P. Kolko, B.A., and Andrea E. Kass, B.A., Cognitive Behavioral Therapy for Weight Management and Eating Disorders in Children and Adolescents, Child Adolesc Psychiatr Clin N Am. 2011 Apr; 20(2): 271–285. . Full text available online. 
- Rebecca Murphy, DClinPsych. et al, Cognitive Behavioral Therapy for Eating Disorders, Psychiatric Clinics of North America Vol 33, Issue 3, Sept. 2010, Pages 611–627. Full text available online.