In Part One of this piece, we took a look at the investment prospects in the two frontline options for treating obesity -- dieting and pharmaceuticals. What we found was a mixed bag -- major potential, to be sure, but many obstacles and the baggage of past failure.

Now, in Part Two, we look at some radical options for the treatment of obesity and which companies are behind them, as well as the potential for a backlash against the food industry.

For the morbidly obese, weight reduction surgery (also called bariatric surgery) is sometimes a viable option. Also sometimes euphemistically called "stomach stapling," these procedures physically alter the stomach so that it holds less food and the patient feels full after only eating a small portion of food.

When successful, bariatric surgery doesn't just produce weight loss of 10 or 15 pounds. Rather, patients can often lose 100 or more pounds. What's more, follow-up data on surgery has suggested that bariatric surgery can effectively cure weight-related maladies like type 2 diabetes, sleep apnea, and high blood pressure.

Of course, these procedures are expensive (and not always reimbursed by insurance), potentially dangerous, and not always effective -- especially when patients are unwilling or unable to modify the behavior that originally made them obese.

The most common bariatric surgical procedures in America are gastric bypass procedures like the Roux-en-Y and biliopancreatic diversions. In each case, physical alterations are made to the stomach and intestines to reduce the stomach's capacity and the patient's ability to consume large portions of food at once.

Make no mistake -- these are serious surgical procedures. As such, there really isn't a clear-cut play on this type of bariatric surgery. True, the procedures use various surgical tools and it might even be possible to find independent surgical centers that offer the procedure, but that's really reaching.

There is, however, an emerging alternative. Gastric banding, a procedure where the size of the stomach is reduced via an expandable elastic band, is quickly gaining popularity. Unlike other procedures, there are no incisions made into the stomach itself. What's more, the procedure is reversible and adjustable. Although some gastric bypass procedures show better initial weight loss, gastric banding catches up over time and has generally lower risks of serious complications.

Inamed (NASDAQ:IMDC) is the closest thing to a pure-play on gastric banding, although even Inamed is not a pure-play option, as the company derives most of its revenue from products targeted at the cosmetic surgery market. What's more, the company has recently agreed to be bought out by Medicis (NYSE:MRX). Nevertheless, Inamed's banding product, the LAP-BAND is becoming increasingly popular and could become a new standard of care in bariatric surgery -- something that would likely still be meaningful for a large company like Medicis.

Johnson & Johnson's (NYSE:JNJ) surgical division is developing a competing product to the LAP-BAND, but has not been approved for use in the United States and probably won't be a factor for a few more years. What's more, investors must realize that buying JNJ just for the obesity angle (be it drugs, devices, or a combination) is roughly akin to buying a jumbo jet just for a few packets of peanuts.

Other approaches
Of course, for some people weight loss is only a minor cosmetic modification. For these people, procedures like liposuction or light-based therapy can generally achieve desirable results.

Mentor (NYSE:MNT) is a leader in the field of ultrasonic liposuction, and Palomar MedicalTechnologies (NASDAQ:PMTI) has partnered with Johnson & Johnson to develop a home-use, light-based system for reducing cellulite.

Again, it must be noted that obesity is only a small part of the overall business plan at these companies (and in the case of Palomar, it's not even a marketed product yet). Accordingly, investors should look at the potential business from obesity as a "bonus," but not a basis for an investment decision.

There has even been research that suggests that delivering pulsed electrical stimulation to the brain can lead to modified eating behavior and weight loss. Although I'm not aware of any large clinical trials under way at present, there are a host of medical device companies with various stimulation devices that could theoretically be pressed into service.

When weight loss just doesn't happen
Despite people's best efforts and best intentions, sometimes obesity proves to be an intractable problem. Sadly, most studies show that, with the exception of patients undergoing bariatric surgery, most people who are obese remain so for the remainder of their lives. Given the constellation of medical problems that goes with obesity, there are certainly companies that will continue to benefit from the ongoing obesity problem.

Sleep apnea is a major underappreciated consequence of obesity, and when left untreated can lead to fatality (through related conditions like heart failure). Both Respironics (NASDAQ:RESP) and ResMed (NYSE:RMD) stand to gain from an ongoing recognition of the serious nature of the disease and a growing acceptance of their products for use in treating the condition.

Elsewhere, the pharmaceutical industry continues to pour money into drugs designed to treat cholesterol and/or hypertension. Whether it's Pfizer's (NYSE:PFE) Lipitor, Sanofi-Aventis' Avapro, or AstraZeneca's (NYSE:AZN) Crestor, the market for these drugs is extremely solid, and the growing prevalence of obesity (along with higher cholesterol and blood pressure) in America should continue to make these markets very attractive for pharmaceutical companies.

Finally, prolonged obesity can also lead to joint damage and/or diabetes. Accordingly, orthopedic companies should continue to see ongoing demand for hip and knee replacements. On the diabetes side, most major pharmaceutical companies are involved in the marketing or development of oral diabetes medication, and insulin manufacturers like Lilly (NYSE:LLY), Sanofi-Aventis, and Novo Nordisk (NYSE:NVO) seem to have little to fear in terms of a declining market.

Who gets hurt
Conventional Wall Street wisdom is that if someone is winning, someone else must be losing. So, who loses in the battle against obesity? For starters, we all lose -- whether we suffer from the health problems of obesity or whether we have to bear the burden of higher overall medical costs. There are, of course, more specific targets as well.

Food companies might be an easy target for future class-action suits. After all, it's not our fault that we stuff our faces with garbage. Oh no. So it must be the fault of those evil, wicked food corporations (after all, how dare they provide us with what we ask them to.). While some companies have been wrist-slapped in the past for misleading or incomplete nutritional information on packaging, I believe we might see food companies sued simply on the basis of the fact that they make products that can make people fat.

Although Congress has toyed with the idea of banning obesity-related lawsuits against restaurants and other food sellers, no bill has passed both chambers and been signed into law. What's more, I'm not aware of any legislative action to attempt to shield food-makers from similar litigation.

So, with that in mind, it's probably only a matter of time before lawyers try to file class-action suits against companies like Coca-Cola (NYSE:KO), Kraft Foods (NYSE:KFT), and SaraLee (NYSE:SLE) in an attempt to shake them down for money. Although I really hope I'm wrong, any company that makes sugar-laden or highly processed food should probably prepare itself to face at least one test case from those who would like to be compensated for their lack of willpower.

Obesity is a problem that isn't going to go away. Unless people en masse choose to reject processed foods and refined sugars and leave their sedentary desk jobs to become lumberjacks or farmers, the basic equation of "too many calories, too little exertion" just won't change.

Since we're all going to pay the price for society's obesity, we might as well try to make a little money off the problem along the way. While every investor must do their own due diligence, I've outlined at least some of the major ways that investors can hope to profit from medical technology aimed at curing, or at least controlling, obesity.

For more on the topics raised in this piece, please check out these other Foolish thoughts:

Fool contributor Stephen Simpson owns shares of Sanofi-Aventis, Amylin Pharmaceuticals, and Johnson & Johnson. The Fool has a disclosure policy. If you liked this piece, recommend it to a friend. If you didn't like it, recommend it to an enemy!