Weight-loss products were examined from the standpoint of scientific study support for each product. Here is a brief summary of the review:
1. Garcinia cambogia extract: The scientific literature support of the weight loss property is mixed. Niacin-bound chromium maintains healthy insulin levels, while Gymnema sylvestre helps regulate weight loss and blood sugar levels. (Preuss et al., 2004) The plant lowered body weight and reduced fat mass in humans. (Heymsfield et al., 1998)
2. Hydroxycut: It is a weight-loss brand. According to Wikipedia, the primary ingredients in this product are caffeine, extracts of Alchemilla vulgaris (lady’s mantle), Oleo europea (wild olive), Cuminum cyminum (cumin), Mentha longifolia (wild mint), and Coffea canephora (coffee bean). Earlier versions of Hydroxycut had Ephedra too. USFDA has declared it unsafe and banned Ephedra which is now not included as an ingredient in this product.
3. Caffeine: Caffeine in beverages, like coffee, tea, energy drinks, colas, products containing cocoa or chocolate, and multiple dietary supplements and medications help in weight loss. Caffeine may reduce feelings of hunger and desire to eat for a brief time. It also appears to increase energy use even when you’re at rest. It stimulates thermogenesis, a process through which your body generates heat and energy for digesting food. These properties of caffeine may slightly boost weight loss or prevent weight gain. (https://www.mayoclinic.org/healthy-lifestyle/weight-loss/expert-answers/caffeine/faq-20058459)
4. Raspberry Ketones: Raspberry ketone safety was reviewed. The lowest recommended daily dose of raspberry ketone (100mg) in weight loss supplements available on the internet is 56 times the established threshold of toxicological concern of 1800 micrograms per day. Raspberry ketone models indicated potential cardiotoxic effects and potential effects on reproduction/development. (Bredsdorff et al., 2015)
5. Glucomannan: Glucomannan was observed to exert beneficial effects by promoting satiety, fecal energy loss, improving lipid and blood sugar parameters. Its safety and efficacy have to be studied and verified. (Keithley et al., 2013) Glucomannan induced bodyweight reduction in healthy overweight subjects. The addition of guar gum and alginate did not seem to cause additional loss of weight. (Birketvedt et al., 2005) A combination of glucomannan, chitosan, fenugreek, Gymnema sylvestre, and vitamin C showed significant body weight and fat loss in obese adults. (Woodgate et al., 2003)
6. Meratrim: A herbal blend containing Sphaeranthus indicus and Garcinia mangostana showed more significant weight loss in obese individuals than a placebo group. (Stern et al., 2013) Meratrim supplement was observed to be well-tolerated and is an effective ingredient for weight management in healthy overweight subjects. (Kudiganti et al., 2016)
7. Conjugated Linoleic Acid (CLA): CLA modulates body fat independent of reduced food intake. It may be more effective at protection against fat mass regain following weight loss than as a weight-loss treatment. (Park et al., 2007). However, this contradicts the findings of others wherein weight loss regain occurred after a weight loss treatment. A study on Chinese subjects claims that supplementation of CLA for 12 weeks in overweight individuals yielded lower obesity indices, with no apparent adverse effects. (Chen et al., 2012)
8. Forskolin: Forskolin gained popularity as a weight-loss supplement in the US in 2014. In a trial conducted over 12 weeks, forskolin was shown to alter body composition favorably and is a possible therapeutic agent for treating obesity. (Godard et al., 2005; Liberman, 2004)
Orlistat, Green Coffee Bean extract, Green tea extract, and Bitter Orange/Synephrine are some other weight loss products.
My review shows that scientific study-based evidence supporting most of the above-listed weight loss products is tenuous and restricted to animal trials.
It is not feasible for me to provide you with details on each of these products. But in a nutshell, obesity is a complex disease. Losing weight is best achieved when we proceed systematically. Check with your physician before consulting a weight loss dietitian. Do not pick up one of the weight-loss diets from those reviewed earlier, or even hire a personal trainer before a medical consultation.
Additional reading:
Natural Solutions for Obesity