In most cases, people who are overweight don't want to be. The stigma of being overweight, particularly in western societies, is often quite strong and can lead to an exceptionally painful emotional outlook. If the stigma and emotional pain weren't enough, there are also the health risks from being overweight to consider. Put it all together and you'll often find overweight people who very much would like not to be overweight. The motivation to lose weight can be a healthy thing, and is mandatory even for weight loss to occur, but overconcern with losing weight can cause real problems.
People often want to make tasks easier and faster to perform. This sort of mindset has been around since forever, and it applies to weight loss as much as anything else. Overweight people often don't want to be overweight, and they often want to stop being overweight immediately. This strong motivation to lose weight can lead to an attempt to push through weight loss rapidly, or to try products that promise to speed up the weight loss process.
Fast weight loss can be seen when stepping on the scale, but fast weight loss is almost always the result of water loss. Water can be removed quickly from the body, which is why dehydration can set in so rapidly without regular water intake. The need for water is absolute, and without a steady supply of water the body will cease to function. Losing a great deal of water weight then can lead to potentially serious forms of health problems.
Losing weight in the form of fat is the ideal in weight loss, but it's a process. Fat is essentially surplus, and surplus takes time to build up. Surplus equally takes time to remove. The fat stored in our bodies took time to make in other words, and it's not going to go away overnight. Methods making the claim to speed up fat loss aren't hard to find. What these treatments typically claim to do is affect metabolism, but they often also affect the heart, usually speeding up its beat rate. Putting something into the body that causes the heart to function abnormally is taking a risk, and that's probably putting in mildly.
When all is said and done, commitment in combination with patience may be the best weight loss strategy there is. Accepting that weight loss is going to take time and effort is a healthy and realistic perspective to have at the onset of any weight loss regimen.