As a registered dietitian I am bound by a code of ethics to practice evidence based medicine. This means evaluating the research on a product or ingredient and making scientifically based recommendations on what the research says. I was recently interviewed by a reporter about a "New Revolutionary" product that could help you lose weight without dieting and exercise. Now, just the words "New" and "Revolutionary" should cause you to put up your red flag not to mention the promise of no dieting and exercise. As soon as the report aired, the hate voicemails flowed in. Keep in mind, money is at stake here. As a user of the product, you can also become a distributor. How dare I say this product may not work or perhaps only by power of suggestion, according to callers. My response to them is SHOW ME THE RESEARCH! Prove to me that the ingredients do what they say they do or that there is even enough of the ingredients in the product to make a difference. The makers of the product in question do not disclose enough information on their website or on the packaging to evaluate just how much of each ingredient the product contains, no means to contact them about the ingredients and where they come from, no indication of independent testing for purity, concentration or contamination, no links to legitimate research, or so much as even a 1-800 number. More red flags!
To make sure you don't get taken for a ride, here is what you should know about some popular weight loss ingredients:
Hoodia - also known as Hoodia Gordonii is a rare South African cactus. Real hoodia is difficult to find because it is a protected plant species, must grow in very hot climates, takes several years to cultivate a new crop, and is very expensive. Many products on the market today have been found to NOT contain the real stuff. To be sure you are getting the real stuff, look for the C.I.T.E.S. certificate and testing by an independent lab. To date, only one scientifically based research study has been published to show that the P57 active ingredient found in Hoodia suppresses appetite. This study was done on rats. Rats are not humans. Research looks promising for humans but safety and efficacy is still in question. Also potential for abuse and malnutrition from taking such a product long-term is real.
Hydroxycitric Acid (HCA) - also known as Citrimax or Garcinia Cambogia, comes from a plant found in Southeast Asia. Initial research on HCA thought that it may prevent fat storage. However, clinical research has failed to prove effectiveness of HCA. Some studies showed a decrease in body weight with HCA at intakes of 1200 mg/day or greater but there were no changes in body fat percentage or appetite ratings. These same studies restricted calorie intake to as low as 1200 calories per day and included other ingredients such as caffeine, chromium, and carnitine. One can not conclude from this that the HCA had the desired effect. In another clinical trial, HCA did not increase subjects ability to burn more fat and stored calories. I will stick with eating less and exercising more. At least that has proven results.
L-Tyrosine - a non-essential amino acid made from an essential amino acid, phenylalanine. Diet aids claim that tyrosine can suppress the appetite. However a search of the scientific literature comes up empty. Tyrosine is involved in the making of thyroid hormones that can effect metabolic processes in the body. Deficiency is rare and taking supplements to boost thyroid hormones has not proven to be effective. People with phenylketouria (PKU) may need a supplement because they can not breakdown phenylalanine to make Tyrosine. Tyrosine supplements may interfere with medications for depression or pain.
Vitamin B6 & B12 - both these vitamins work in allowing our body to properly use and store both fats and carbohydrates. They help our energy producing systems work efficiently. One study in the Journal of Alternaitve and Complementary Medicine found that overweight or obese middle aged (45) long-term users of multivitamins, B6 and B12 supplements gained less weight over time. So they didn't lose weight, they just didn't gain as much. The researchers concluded that more research was necessary before recommendations could be made for B6 and B12 supplements for weight loss. Also other studies have confirmed that supplement users tend to have healthier lifestyle habits that help them to control weight gain. So for now, I will continue to get my B vitamins from lean meats, whole grains, legumes, and nuts.
Gaurana - a.k.a. herbal caffeine. It stimulates the central nervous system, increases thermogenesis (burning of energy to create heat), and can act as a diuretic, causing water to be lost from the body. It also may have some antioxidant potential similar to coffee. However, the research fails to prove that this ingredient results in weight loss. Studies I was able to fine used multiple ingredients and change in body weight was not significant compared to control groups. In one study the group receiving the supplement did have a change in body fat but they were also exercising. If you are taking any prescribed medications, you may want to check the fine print to be sure this herb will not effect it. Blood pressure medications are often affected by herbal supplements and caffeine.
Bottom line: The power of suggestion of a diet aid is very powerful. If you believe it will work chances are it will. But before I endorse a product, SHOW ME THE RESEARCH!