To answer your question, it will depend on the context that you are referring to. If you are hoping to achieve reduction of large amount of weight lost or major reduction of fat, non-surgical fat reduction is the wrong option.
The correct way to reduce large amount of fat is diet and exercise, provided that there is no underlying medical condition causing weight gain, such as hypothyroidism.
Surgical liposuction is able to remove several kilogram of fat in one session, highly effective and of lasting result. A good treatment as long as the patient is medical fit and is willing to accept the risks and complications associated.
There are many non-surgical fat reduction treatment and they are not all equal. They should not be called non-surgical liposuction as well as there is no suction of the fat out of the body.
We can broadly divide the various non-surgical fat reduction methods into those that reduce the number of fat cells (fat cell apoptosis) and those that only reduce the fat content in the fat cell (lipolysis).
Fat are also stored in different part of our body. I presume that you are referring to the those that are under the skin, i.e. those in the sub-cutaneous fat layer over the back of arm and around the waist and abdomen. For those fat that is around the muscle fibers, it would be best reduced through proper diet and exercise.
For subcutaneous fat, I find that treatment that could result in apoptosis would be better. The reduction in number of fat cell gives a longer lasting result, as long as you do not gain too much weight. It may be achieved through freezing (e.g. Coolsculpting with Zeltiq) or high intensity focused ultrasound (e.g. Liposonix). Radiofrquency technology usually achieve only lipolysis (reduction of fat content) and hence the effect will not last. That said, all these all methods only reducing about 20-25% of the treated fat. If you have only a small amount of fat to reduce or if you are trying to get improve the shape after achieving the weight lost, these treatments are great! It is also safer and has less downtime compared to surgery.
For fat in the abdominal cavity (visceral fat around the organs), all the above treatments, including surgery) will not be effective.
Diet control and exercise are the best for visceral fat. Some machines, such as Inbida, uses a proionic system (basically a radiofrequency with a specific 448 KHz frequency), is effective in stimulating various tissues, including the muscle, ligament and fat cell. It was first used for muscle recovery and has also been found to be good for mobilising the fat content. Some patients noticed that they are better able to reduce the visceral fat through diet and exercise after Indiba treatment.
So after confusing you with a long essay, the conclusion is that
1) Surgical liposuction is able to achieve larger volume of fat reduction in one session (with some risks associated with anaesthesia and surgery),
2) Non-surgical fat reduction is great for shaping and small area reduction
3) Proper diet (not starvation) and exercise is the key for weight loss
Have a great weekend and a good life!
Dr Elias Tam