Gastric bypass surgery is recommended for the morbidly obese who has not been successful in weight loss after many attempts.

Treatment - As a last resort, if nothing else has worked
Weight loss surgery - gastric bypass - is an option for the morbidly obese. I am not thrilled about the prescription weight loss medications since many have serious side effects. There may be some weight loss centers that could offer help, but not all of them are worth the money and not all quick weight loss centers can be trusted.
     Weight-loss surgery works not just by restricting the amount of food absorbed by the body, it seems. In part, at least, it leads to weight loss by causing hormone changes that reduce appetite and improve sugar metabolism. Patients who undergo stomach bypass have increased levels of two hormones, PYY and GLP-1, which would be expected to produce sensations of fullness after eating. In addition, patients have changes in their insulin response that would lead to improved blood sugar levels. By contrast, patients who lose a comparable amount of weight through gastric banding, a procedure in which the size of the stomach is restricted but it's not actually bypassed, do not show these hormonal changes.

Gastric Bypass Surgery less safe with age
The risk of complications after weight loss or "bariatric" surgery increases for each additional year over age 60. A "duodenal switch" operation is more likely to result in complications than the more commonly performed gastric bypass operation. The gastric bypass results in weight loss by surgically "bypassing" the stomach, while the duodenal switch involves removing most of the stomach and reconfiguring the digestive tract to limit the amount of fat and calories that can be absorbed by the intestines.

Take B Vitamins after Gastric Bypass Surgery
Doctors need to check for B Vitamin status, particularly thiamine deficiency in patients after they've had gastric bypass surgery for obesity. That's the conclusion of a case study that found vitamin B1 deficiency can lead to a serious neurological condition called Wernicke encephalopathy. The report involved a 35-year-old woman who developed numerous problems -- nausea, anorexia, fatigue, hearing loss, eye movement abnormalities, forgetfulness and ataxia (problems with muscle movement) -- after she had gastric bypass surgery. Within 12 weeks of her surgery, she had lost 40 pounds and had trouble walking and concentrating. A magnetic resonance imaging (MRI) scan detected abnormal signals in various areas of the woman's brain, indicating a deficiency in vitamin B1. This vitamin, also known as thiamine, is essential for carbohydrate metabolism and normal nervous system functioning. The woman's intravenous dose of vitamin B1 was increased to 100 milligrams every eight hours, which led to a decrease in abnormal eye movement and confusion. A follow-up MRI 11 days later showed the abnormal brain signals had decreased. The report appears in the Dec. 27, 2005 issue of Neurology.

Nutritional and Herbal Weight Loss supplements to consider before Gastric Bypass Surgery for weight loss
Countless herbal weight loss products are sold that contain some of these supplements.
5-HTP is a nutrient that helps curb appetite in some individuals . 5-HTP, by converting into serotonin, can be used temporarily to improve will power and decrease the urge to eat until more established weight loss habits are in place.
Acetyl-l-Carnitine may reduce appetite in some individuals
Alpha lipoic acid may also reduce appetite
Hoodia is a cactus plant extract from the Kalahari desert in South Africa that has been getting a lot of attention lately as a weight loss pill.
Green tea extract is sometimes used for weight loss.

Long term outcome
N Z Med J. 2013 Nov 22. Long-term outcomes in gastric bypass patients with and without type 2 diabetes--Waitemata District Health Board experience. Dramatic early postoperative improvement or resolution of type 2 diabetes mellitus (T2DM) has been widely reported after bariatric surgery but there is limited long-term data on T2DM outcome. Moreover, data on long-term weight outcomes of government funded bariatric surgery in New Zealand is lacking. We report weight and glycaemic outcomes in subjects with and without T2DM who underwent gastric bypass surgery (GBP) at Waitemata District Health Board (WDHB). GBP resulted in substantial weight loss in essentially all subjects, and weight loss was well maintained over time. GBP also had dramatic and favourable effect on T2DM but did not uniformly result in prolonged diabetes remission.