Written by Jim LaValle, R.Ph., CCN
A recent headline from a study on hoodia (an African plant often used in weight loss pills) once again has people asking me about weight loss supplements. Sales of the “weight loss in a bottle-type supplements” sure don’t seem to be slowing down. Do they work? Can they help, at least? Here’s what you need to know.
What is hoodia? Does it work?
The story of hoodia is somewhat of a cautionary tale when it comes to weight loss products. Hoodia is a succulent plant that is used by the people of the Kalahari Desert to lower appetite and thirst when food and water are scarce. This unique plant and its action of helping to reduce appetite caused some industry players to spend millions of dollars evaluating the herb to see if it was effective for weight loss. An early study looked promising. It was a fairly small, unpublished study which found that when people were given hoodia, they consumed 30% fewer calories than people given placebos. This led to further study by Pfizer, who found that the active ingredients in the plant were very difficult to isolate and, much to their dismay, that hoodia could cause liver damage. Because many weight loss supplements include hoodia as an ingredient, I was very glad to see that another human trial was finally completed recently.
The trial gave clinical dosages of a purified hoodia extract to 25 women with high body fat percentages, and compared their calorie intake and weight loss to 25 women given a placebo product. The study found that the hoodia group had reduced their calorie intake by 24% over baseline while the placebo group had decreased their calorie intake by 18%. Interestingly, these reduced calorie intakes did not lead to any loss of body weight or body fat. In addition, while the placebo group had no side effects, the group taking the hoodia supplement had increases in blood pressure and heart rate as well as increased bilirubin and the liver enzyme called ALP. Also, the group taking hoodia had many other side effects including headaches, nausea and vomiting. The side effects combined with the lack of efficacy for weight loss obviously led the researchers to conclude that hoodia would not be a good candidate for a weight loss product.[i]
Now, what is so amazing to me is that the studies finding potentially damaging side effects have not stopped the manufacturers from using hoodia as an ingredient in their weight loss supplements, or at least saying the products contain hoodia. A lab analysis found that of 13 products tested, only 6 actually contained hoodia,[ii] which, in this case, is probably a good thing.
Are there any weight loss supplements that work?
Let me put it this way. There may be some that are somewhat effective for some people depending upon whether the ingredients in the product happen to address your physiological needs, e.g., insulin resistance, which is a culprit in a lot of weight gain.
Most weight loss supplements are a mixture of active ingredients, and there is usually a good rationale for the ingredients. Some of the most common ingredients have a decent amount of research, but there is still a big BUT. Most products do not contain enough of the active ingredients to get the same results seen in studies. In addition, it can be hard to tell exactly how much of an active ingredient a product contains because the manufacturers will use several ingredients together as a part of a patented blend of ingredients, which they lump into a name they make up. Here are some examples:
Blood sugar-regulating ingredients
Many of the ingredients in weight loss supplements are supposed to act on blood sugar and insulin regulation. This is a good mechanism of action because insulin resistance truly is a factor in weight gain.
Chromium – Helps insulin work better for reduced insulin output. Typical dosages I’ve seen are 10 to 120 mcg. Studies have used up to 2000 mcg in severely insulin-resistant diabetics. A study showing some efficacy for reducing food intake and slight weight loss (about 1 lb. in 8 weeks) was 1000 mcg.[iii]
Vanadium – This has insulin-like action and improves blood sugar and cholesterol profiles. Studies have used anywhere from 250 mcg to 150 mg,[iv] a much larger “research only” dosage. The safe upper limit is 1.8 mg. Weight loss products I’ve seen have contained anything from 10 to 500 mcg, dosages that are much lower than the studies.
Alpha lipoic acid – Has been studied extensively in diabetics for insulin resistance. The effective dosage is 600 mg two or three times a day. This is one where the usual dosages in weight loss supplements are woefully lacking, containing anything from only 10 to 100 mg.
Magnesium – May contain anywhere from 20 to 100 mg. Effective dosages are 250 to 500 mg per day minimum.
Gymnema sylvestre – This is an herb, which actually has a good bit of research showing efficacy for blood sugar regulation with human studies. Studies showing that it may reduce cravings for sweets and help weight loss have been rat studies.[v], [vi] Dosages in studies are from 250 mg to 600 mg one to three times a day. Dosages in weight loss products are sometimes not clearly identified, but they typically aren’t over 200 mg.
Increased metabolic rate
Other ingredients are substances that have been shown in studies to increase metabolic rates slightly, like green tea, caffeine and garcinia cambogia.
Green tea – This is an ingredient with some of the most impressive studies for weight loss. One of the highest quality green tea products is a green tea phytosome; a study of this particular product showed that when taken along with a low-calorie diet, it led to a 14 kg weight loss in 90 days compared 5 kg weight loss in the diet-only group.[vii] The dosage in this study was 250 mg twice a day. Again the key here is quality and quantity. Green tea products should contain 90% polyphenols and at least half of the polyphenols should be the active compound known as EGCG.
Caffeine – This is an ingredient that is sometimes way overdone, with some products containing the equivalent of 30 cups of coffee per day. Needless to say, if a product contains caffeine it can cause a person to feel very jittery and unable to sleep. Effective dosages have ranged from 80 to 200 mg per day. I’ve seen products containing anywhere from 40 to 1400 mg.
Stress reduction/craving reduction
Rhodiola – Rhodiola is a great ingredient that really has been shown to help reduce the effects of stress on the body.[viii] The effective dosage range is 150 to 300 mg, one to three times a day, and these should be standardized extracts that contain at least 3% to 5% rosavins. I have seen products that contain only 50 mg and do not state that they are standardized.
These are just a few examples. I have seen many diet products with a mixture of these and other ingredients, such as cinnamon, or antioxidant ingredients such as resveratrol and curcumin. For good ingredients like these, the bottom line is that the dosages have to be high enough. Then there are the unproven ingredients like acai. It is an antioxidant,[ix] but it’s just not proven for weight loss, no matter how many claims you see. Then there are ingredients that may have some study like the thermogenic products bitter orange (citrus aurantium) and garcinia cambogia, but they do cause jitteriness, which means they are stimulants and over time can be hard on the body. Side effects can include increased heart rate and blood pressure.
The bottom line: Use caution and look for high quality.
When it comes to products available in over-the-counter retail outlets, I would be very cautious. The unfortunate truth is there is no easy weight loss miracle pill, and there have been many instances of adulteration in products off of retail store shelves and Internet products. Are you willing to sacrifice adrenal effects, burnout, sleep problems and even high blood pressure in exchange for hope of a few lost pounds?
However, some high-quality products are available that can give you an edge if they contain adequate dosages of good ingredients. For example, I know several professional practices that carry products with blends of some of the better-proven ingredients. (Not to get in a cheap plug, but Life Time’s Lean Source is one such product. It contains one of the best proven ingredients, green tea, along with blood sugar-supporting chromium, muscle-building CLA and thyroid-supportive 7 Keto DHEA.) But these professionals also take the time to evaluate and address metabolic issues that may be contributing to weight gain.
As you have hopefully read in many articles from Life Time, the reasons for weight gain are many and varied; therefore, the solutions to weight loss will be multifactorial. Your best hope for long-lasting weight loss is identifying underlying metabolic disruptions and taking steps to address them.
This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.
[i] Blom WAM, et al. Effects of a 15-d repeated consumption of Hoodia gordonii purified extract on safety, ad libitum energy intake, and body weight in healthy, overweight women:a randomized controlled trial. Am J Clin Nutr Oct 12, 2011.
[iii] Anton SD, et al. Effects of chromium picolinate on food intake and satiety. Diabetes Technol Ther. 2008 Oct;10(5):405-12.
[iv] Cusi K, Cukier S, DeFronzo RA, Torres M, Puchulu FM, Redondo JC. Vanadyl sulfate improves hepatic and muscle insulin sensitivity in type 2 diabetes. J Clin Endocrinol Metab. Mar2001;86(3):1410-1417.
[v] Imoto T, Miyasaka A, Ishima R, et al. A novel peptide isolated from the leaves of Gymnema sylvestre - I. Characterization and its suppressive effect on the neural responses to sweet taste stimuli in the rat. Comp Biochem Physiol A 1991;100(2):309-314.
[vi] Luo H, et al. Luo H, Kashiwagi A, Shibahara T, Yamada K. Decreased bodyweight without rebound and regulated lipoprotein metabolism by gymnemate in genetic multifactor syndrome animal. Mol Cell Biochem. 2007 May;299(1-2):93-8.
[vii] Di Pierro F, et al. Greenselect Phytosome as an adjunct to a low-calorie diet for treatment of obesity: a clinical trial. Altern Med Rev. 2009 Jun;14(2):154-60.
[viii] Hung SK, Perry R, Ernst E. The effectiveness and efficacy of Rhodiola rosea L.: a systematic review of randomized clinical trials. Phytomedicine. 2011;18(4):235-44.