Maintaining one’s weight is the toughest task for many people, not because of the efforts that have to be put in but because of the mindset needed to follow the weight reduction steps. You have to notice that there are several ways of losing weight, the chief amongst them being watching your diet and following an exercise regime. However there are certain basic things that you have to remember in these major categories of maintaining weight. In order to motivate yourself to lose weight it is better to take help from professionals in the beginning.
This is because you will be more motivated to maintain a weight when you have a specific plan in mind. Hence in case of diet, a dietician will be of great help as he will devise the ideal diet plan for you once he knows your body type. Similar is the case of exercising. You can take help from a personal trainer the beginning who will devise an exercise routine for you. And you can even adopt the carrot and stick approach in both these cases.
If you have eaten food containing fats on a particular day then you should stay away from these foods for some period of time. Likewise if you have successfully followed your diet plan for the week then you can treat yourself to an ice cream. You can apply the same carrot and stick approach for your exercise regime. So treat yourself if you have regularly exercised for a week and punish yourself if you have missed out on a few sessions.
The other way of motivating yourself to maintain weight is to read about the lifestyle of a person whose body you absolutely adore. This person could be anyone from a celebrity to someone in your house or just a friend. You can ask this person about how he or she maintains health and how the person has been able to successfully fend of unwanted weight. Hence we see that if you want you can derive motivation from a lot of sources and factors to lose weight. In case of food you should actually try not to treat yourself with food for motivation if you do a particular task successfully. In this case the purpose of shedding weight may not get solved. Instead you can treat yourself to a movie or a concert or anything that suites your liking.  
Place a higher aim for yourself then you can actually do. This way you will be able to achieve at least 80% of your goals. For example, you can aim for doing exercises every single day and then try to accomplish the task. In this case it would not be bad even in case you manage to do exercises for just about 5 days a week. You can even keep a large photo of a person whom you always look at when you want to lose weight. When you look at this person you will automatically be motivated to look as lean and fit as the person in the frame.