Introduction: Eating is one of the fundamental sources of happiness. Slimming diets would deprive you of this very enjoyment without granting something else instead, for example, proper eating behaviours for life or a permanent solution for overweight-related problems. Aim: This paper aims to investigate the psycho-dynamic relationships that might be the reason for the failure of all diets and slimming diets. Method: Analysing overweight, obesity and the failure of slimming diets with the help of the cognitive behavioral therapeutic approach. Results: By applying the principles confirmed and laid down by the cognitive behavioral therapy, we can identify specific ethological causes present in dieting and gaining weight behaviours that can successfully be used in curative symptom and problem oriented psychotherapy. Conclusion: In summary it can be stated that it is advised to approach the defined objective slowly, in small steps. With the help of learning methods and the continual transformation of the environment, obese individuals, having shred their own unwanted behavioral attitudes, can not only build up new attitudes and transform them into new desirable habits but will also have their personalities chiselled.