When paired with a calorie-restricted diet and exercise, some diet pills can boost weight loss. Unfortuantely, most of the diet pills on the market have not been evaluated and approved by the Food and Drug Administration. In fact, the only FDA-approved over-the-counter diet drug at this time is GlaxoSmithKline's Alli, a lower-dose version of the prescription weight loss drug Xenical.
Orlistat, the chemical name for the active ingredient in both Xenical and Alli, works by attaching itself to enzymes in the digestive tract to stop about 25 percent of the fat intake from each meal. That fat later passes through the body undigested, which can lead to gastrointestinal problems such as diarrhea.
At its prescription strength, clinical trials show that Orlistat helped those on a fat-restricted diet lost 13.4 pounds over the course of a year compared with 5.8 pounds in those who only dieted. That makes for twice the weight loss, but only a real increase in loss of about eight pounds. Non-prescription strength Alli provides half the dose of Xenical, but comparable results with those using the product experiencing a similar doubling in weight loss compared to those on placebo.
Alli costs about $1.20 per pill, or $1,314 a year if taken with every main meal. Given given Orlistat's 7.6 pound average increase in weight loss in a year, that works out to $172.90 a pound.
Alli's side effects should be taken into consideration: users can experience "gas with oily spotting", "loose stools", "difficulty controlling bowel movements" according to the product website. A recent FDA safety review has also found that Orlistat can lead to severe liver damage in rare cases. The company advises that those who experience yellow eyes or skin, dark urine or loss of appetite should stop taking Alli because of possible liver damage.
Alli and Xenical also absorb some necessary fat soluble vitamins from each meal, which can result in nutritional deficiency.
Bottom-Line Estimate: You SAVE $12.50 per pound you lose.
Losing weight the old fashioned way, by just eating less, is the cheapest "diet plan" yet. Though most diet plans are geared towards limiting certain foods and boosting other, healthier options, you can also lose weight by simply eating a bit less of what you already eat, diet experts say.
Nutritionist Mark Haub, an associate professor of nutrition at Kansas State University, proved this point recently when he experimented with limiting his caloric intake while incorporating snack cakes such as Twinkies and Nutter Butters in his daily fare. Even with two to three sweet treats a day alongside things like steak, whole milk, fruits and veggies, he made sure to eat only 1,800 calories a day and he lost 15 pounds in a month.
That's not to say that "simply" eating less is a simple feat, but if you can manage it, you could actually save money by dieting. Haub's Twinkie-heavy dietis not recommended, but as long as you cut back on what you normally eat by about 25 percent, you can expect to lose about a pound a week, says Ayoob.
"A pound of fat is 3,500 calories so to lose a pound of week, you'd need to trim off 500 calories a day from what you eat. Based on the standard 2,000 calorie intake per day, that would amount to a 25 percent decrease in caloric intake overall," Ayoob says.