What's Wrong With Diet Pills to Lose the Extra Pounds?

Diet products are a multi-billion dollar industry, which is hardly surprising considering many of us are overweight, but find losing weight difficult.

Manufacturers of these diet products make tantalizing claims about quick fixes – simply use their product, watch the fat melt away, and all without diet and exercise – but are these claims to be believed?

Diet pills are popular weight loss products. They come in prescription, over-the-counter (OTC), and herbal forms and act on the body in different ways depending on their ingredients. Some products facilitate weight loss by preventing the body’s absorption of fat, in turn causing the body to take in fewer calories. There can be unpleasant side effects, however, like cramping and loose bowels, but these often diminish after consistent use of the pills for a couple of months.

Other diet pills work on the re-uptake of neurotransmitters, such as serotonin and dopamine, that are associated with feelings of appetite satiation. Belviq, a prescription diet pill that works through the activation of the serotonin 2C receptor, was recently approved by the FDA.

A two-year study of Belviq suggested that it was associated with a small degree of weight loss (about 3% of BMI) and it did not activate the serotonin 2C receptor, which was associated with heart valve damage frequently experienced by users of fenfluramine (fen-phen) in the 1990s, but studies are ongoing and concerns remain regarding whether Belviq is associated with tumors. Still other diet pills are proposed to facilitate weight loss through suppressing appetite by increasing the body’s metabolic rate.

Unlike prescription and OTC diet pills, herbal weight loss remedies have little regulation, as the FDA considers them food products rather than medications. The FDA retains the ability to pull these products from the market, however, as they did with the potentially dangerous ephedra in 2003. Since herbal pills must not adhere to strict regulations, there are no assurances that these diet products can meet the promises of their manufacturers. So most likely are not as effective as they should be, although there are some decent ones.

Do diet pills actually work?

Research published in the American Journal of Preventive Medicine in 2012 suggested that among a large sample of obese adults attempting to lose weight, three times as many adults were using OTC or herbal diet remedies than those using prescription pills. However, only those who were using prescription pills were able to maintain a loss of 5% to 10% of their body weight over a year, suggesting that OTC and herbal diet remedies have little long-term efficacy.

But there remain unanswered questions about the effects of taking prescription pills longer than two years. Unknown are the long-term side-effects, the possibility of weight loss plateaus, and the degree of weight gain experienced when the medication is no longer taken. Moreover, prescription pills are only available to those who are obese (BMI of 30 or greater), and not to those who are less overweight, but would still like to slim the waistline.

In sum, prescription drugs have shown to be a moderately effective method to help obese adults kick start weight loss. Even much more popular, however, are OTC and herbal diet pills, whose evidence of efficacy is nonexistent. It seems that the only proven healthy method of long-term weight loss remains a reduced calorie diet and exercise. In contrast to the enticing claims, there are no quick fixes for weight loss.

more information on diet pills on our weight loss page

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