Just restricting a diet is simply not enough. One must work to reach their goal, and this can be put into context anywhere.
This can be like studying. When many people are done studying, they usually reward themselves at the end. This "reward" keeps them under motivation to get that "reward". Afflicted people can follow this path. For instance, many people considered obese find it very difficult to control their urge. However, if a treat comes into play, that person will be determined.
Now you can task that person with exercising to reach this reward. Over time, they will gradually begin to conquer their obstacle. As they lose less weight, exercising will become much more efficient for them, therefore accelerating the process. Especially when paired with high calorie-burning, very successful results are to ensue. People's journeys of weight loss clearly demonstrates the possibility of this.
Finding a source of motivation can be very difficult. That is why it is essential to question a person's interests beforehand. When set in motion, the person's behavior must be monitored strictly to ensure the best results possible. Obviously, there is much more to this and just working out, but working out can play the biggest role. In addition, support from others is also necessary. Not living up to people's expectations isn't something anyone would want, which therefore keeps them motivated to keep trying. In the end, it will prove to be all worth it.
These are expected of a healthy person.
(Sarcasm) Obesity has gotten to the point where even celestial objects in the universe began to work out, the Runnning Man Nebula. Would a person want to be outdone by a nebula? No. This image can be used with sarcasm to motivate people to work out.