Dietary Supplements for Weight Loss. What You Need to Know

With little oversight over dietary supplements or evidence that they work, it is important not to believe the advertising claims. Dietary supplements promise incredible weight loss, but medical studies show most do not work, and some may be harmful. Despite this medical evidence, Americans spend over $2 billion a year on weight loss supplements. 

Problems with Dietary Supplements 

Unlike FDA-approved medications, dietary supplements do not have to be proven to be effective or safe before being advertised or sold. They are not rigorously regulated by the FDA or state boards of pharmacy. 

• Some people believe products are safe if they are advertised as “natural” and do not require prescriptions. 

• There is little evidence that any herbal or over-the-counter weight loss aid helps with significant weight loss. 

• Although advertisers claim that studies support their products, the studies are almost always unscientific and poorly done. They do not prove the product is effective or safe. 

What are the Risks of Taking Dietary Supplements? 

Some dietary supplements may cause heart problems, liver or kidney problems, or even death. The FDA warns against several products that contain toxins or banned drugs. An example of lack of safety is HCG shots which are advertised as “natural.” They are sold inappropriately as part of miracle weight loss diets. 

• HCG is a hormone produced during pregnancy. 

• The FDA approved the shots to treat some cases of infertility. However, it required a label stating HCG has not been proven to help with weight loss.

 • Still, HCG shots are used with extreme calorie limits of 500 calories a day. Studies have shown this does not work for weight loss and is likely unsafe.

Safe Over-the-Counter Dietary Supplements 

There are two over-the-counter options for losing weight that have been proven effective with scientific studies. 

The first is Alli®: It is not a dietary supplement. Alli is an over-the counter version of orlistat (a prescription medication approved by the FDA in 1999). 

• Several studies show that orlistat can help people lose a reasonable amount of weight and keep it off long term.

 • One study showed that orlistat (at the full prescription dose, which is twice the dose of over-the-counter Alli) led to 10% body weight loss over 1 year when used with a behavioral weight loss program. 

• The people in this study maintained their weight loss after 4 years. They were also 45% less likely to develop diabetes than people who did not take it. 

The second is fiber supplements.

• Fiber supplements help make you feel full and slow digestion. 

• The most commonly used fiber supplement is psyllium. It leads to small weight losses and may also lower cholesterol. 

• At recommended levels, the risk of side effects is low. 

• Or increase fiber in your diet and get the same benefits.

Conclusion: Proceed with Caution

While dietary supplements may seem like a quick fix for weight loss, it's essential to approach them with caution and skepticism. The lack of regulation and scientific evidence means that many supplements on the market may not deliver the promised results and could potentially harm your health. Before considering any weight loss supplement, consult with a healthcare professional to explore safe and effective alternatives tailored to your individual needs and goals. Your health and well-being deserve evidence-based strategies that prioritize long-term success and safety.

By Scott Kahan, The Obesity Society Clinical Committee Chair, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. The Obesity Patient Page is a public service of The Obesity Society (TOS) and its Clinical Committee. These recommendations are appropriate in most instances, but they are not a substitute for medical diagnosis. Consult your healthcare provider for specific information concerning your personal medical condition. This page may be photocopied non commercially by healthcare practitioners to share with patients. Healthcare practitioner is defined as being legally permitted to provide healthcare services and advice as defined by governing state laws and regulations .