Detox programs are popular in California and I know of people who are trying them. Of course there are programs out there that people have to pay for and this is one major motivator why some companies (and people) advocate for it. In most case they are just misinformed. There is very little difference between this and supplement companies that promote their products even when they are not healthy or helpful. What people don't realize is that there are dangers to using these programs and they are likely to gain even more weight when they are done.
They are unlikely to gain anything out of these detox programs and should focus on lifestyle and exercise changes.
What I have heard from people who have completed a detox program is that they often feel sick but do drop a few pounds; in their minds it is worth it! This includes weakness, fatigue, dizziness, and low energy. When they are done and begin to eat their normal routine again they usually gain the weight back because their metabolism has slowed. The same problem with all quick calorie restriction diets and this is why doctors no longer promote them without long term changes.
Unhealthy detox programs:
Serious calorie restriction, lack of nutrients, not eating well for days, with minimal protein and fiber. People who use these programs often have existing problems with weight and think this is a "magic" trick that leads to a quick solution. Unfortunately, they could cause themselves serious illness and sickness if they deprive their body of nutrients and blood sugars drop too low. In some cases it can lead to malnutrition and even coma.
Why most weight loss programs like Weight Watchers have changed their program?
They no longer seek to radically limit your calorie intake but to instead teach you about healthy nutrition for lifestyle changes. In this case, they now have it right and are focused on eating proteins, vegetables, fiber, whole grains, and other foods that provides your body with natural nutrients it needs. Weight loss is a by product of a healthier lifestyle.
A healthy detox program:
If you are getting rid of bad fats, eating whole grains, protein, minimizing unnecessary carbohydrates your body doesn't currently need, and consuming lots of vegetables/fruits then "yes" this detox program will work. It isn't about calorie restriction. It is about eating healthy and could be maintained for a long time to improve health. Yet...this really isn't a detox program....it is a eating healthy program!
Of course you will need to check with your doctor as to whether any detox program beyond simply eating healthy will make a difference. More than likely they will give you some nutritional and exercise advice.There are lots of people selling all types of things that we don't need and yet 2/3rds of Americans are overweight and obese!