- Reliable and relatively consistent scientific data showing a substantial health benefit.
- Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
- For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.
For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
Egg protein may reduce appetite and help induce weight loss.(more)
Read details for informationOne study found hoodia to be effective at curbing appetite. (more)
1. Stanko RT, Tietze DL, Arch JE. Body composition, energy utilization, and nitrogen metabolism with a 4.25-MJ/d low-energy diet supplemented with pyruvate. Am J Clin Nutr 1992;56:630-5.
2. Stanko RT, Reynolds HR, Hoyson R, et al. Pyruvate supplementation of a low-cholesterol, low-fat diet: Effects on plasma lipid concentration and body composition in hyperlipidemic patients. Am J Clin Nutr 1994;59:423-7.
3. Kalman D, Colker CM, Wilets I, et al. The effects of pyruvate supplementation on body composition in overweight individuals. Nutrition 1999;15:337-40.
4. Kalman D, Colker CM, Stark S, et al. Effect of pyruvate supplementation on body composition and mood. Curr Ther Res 1998;59:793-802.
5. Kreider R, Koh P, Ferreira M, et al. Effects of pyruvate supplementation during training on body composition & metabolic responses to exercise. Med Sci Sports Exerc 1998;30:S62 [abstract].
6. Ivy JL, Cortez MY, Chandler RM, et al. Effects of pyruvate on the metabolism and insulin resistance of obese Zucker rats. Am J Clin Nutr 1994;59:331-7.
1. Thom E, Wadstein J, Gudmundsen O. Conjugated linoleic acid reduces body fat in healthy exercising humans. J Int Med Res 2001;29:392-6.
2. Mougios V, Matsakas A, Petridou A, et al. Effect of supplementation with conjugated linoleic acid on human serum lipids and body fat. J Nutr Biochem 2001;12:585-94.
3. Zambell KL, Keim NL, Van Loan MD, et al. Conjugated linoleic acid supplementation in humans: effects on body composition and energy expenditure. Lipids 2000;35:777-82.
4. Riserus U, Berglund L, Vessby B. Conjugated linoleic acid (CLA) reduced abdominal adipose tissue in obese middle-aged men with signs of the metabolic syndrome: a randomised controlled trial. Int J Obes Relat Metab Disord 2001;25:1129-35.
5. Smedman A, Vessby B. Conjugated linoleic acid supplementation in humans—metabolic effects. Lipids 2001;36:773-81.
6. Blankson H, Stakkestad JA, Fagertun H, et al. Conjugated linoleic acid reduces body fat mass in overweight and obese humans. J Nutr 2000;130:2943-8.
7. Whigham LD, Watras AC, Schoeller DA. Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans. Am J Clin Nutr 2007;85:1203–11.
8. Kreider RB, Ferreira MP, Greenwood M, et al. Effects of conjugated linoleic acid supplementation during resistance training on body composition, bone density, strength, and selected hematological markers. J Strength Cond Res 2002;16:325-34.
1. Gades MD, Stern JS. Chitosan supplementation does not affect fat absorption in healthy males fed a high-fat diet, a pilot study. Int J Obes Relat Metab Disord 2002;26:119-22.
2. Guerciolini R, Radu-Radulescu L, Boldrin M, et al. Comparative evaluation of fecal fat excretion induced by orlistat and chitosan. Obes Res 2001;9:364-7.
3. Zahorska-Markiewicz B, Krotkiewski M, Olszanecka-Glinianowicz M, Zurakowski A. Effect of chitosan in complex management of obesity. Pol Merkuriusz Lek 2002;13:129-32 [in Polish].
4. Kaats GR, Michalek JE, Preuss HG. Evaluating efficacy of a chitosan product using a double-blinded, placebo-controlled protocol. J Am Coll Nutr 2006;25:389-94.
5. Ho SC, Tai ES, Eng PH, et al. In the absence of dietary surveillance, chitosan does not reduce plasma lipids or obesity in hypercholesterolaemic obese Asian subjects. Singapore Med J 2001;42:006-10.
6. Pittler MH, Abbot NC, Harkness EF, Ernst E. Randomized, double-blind trial of chitosan for body weight reduction. Eur J Clin Nutr 1999;53:379-81.
7. Muzzarelli RA. Clinical and biochemical evaluation of chitosan for hypercholesterolemia and overweight control. EXS 1999;87:293-304 [review].
Biochemical and animal research show that HMB has a role in protein synthesis and might, therefore, improve muscle growth and overall body composition when given as a supplement. However, double-blind human research suggests that HMB may only be effective when combined with an exercise program in people who are not already highly trained athletes. Double-blind trials found no effect of 3 to 6 grams per day of HMB on body weight, body fat, or overall body composition in weight-training football players or other trained athletes.1, 2, 3, 4, 5 However, one double-blind study found that 3 grams per day of HMB increased the amount of body fat lost by 70-year old adults who were participating in a strength-training program for the first time.6 A double-blind study of young men with no strength-training experience reported greater improvements in muscle mass (but not in percentage body fat) when HMB was used in the amount of 17 mg per pound of body weight per day.7 However, another group of men in the same study given twice as much HMB did not experience any changes in body composition.
1. Ransone J, Neighbors K, Lefavi R, Chromiak J. The effect of beta-hydroxy beta-methylbutyrate on muscular strength and body composition in collegiate football players. J Strength Cond Res 2003;17:34-9.
2. Kreider R, Ferreira M, Wilson M, et al. Effects of calcium beta-HMB supplementation with or without creatine during training on body composition alterations. FASEB J 1997;11:A374 [abstract].
3. Slater G, Jenkins D, Logan P, et al. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation does not affect changes in strength or body composition during resistance training in trained men. Int J Sport Nutr Exerc Metab 2001;11:384-96.
4. Kreider RB, Ferreira M, Wilson M, Almada AL. Effects of calcium beta-hydroxy-beta-methylbutyrate (HMB) supplementation during resistance-training on markers of catabolism, body composition and strength. Int J Sports Med 1999;20:503-9.
5. Slater GJ, Jenkins D. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation and the promotion of muscle growth and strength. Sports Med 2000;30:105-16 [review].
6. Vukovich MD, Stubbs NB, Bohlken RM. Body composition in 70-year-old adults responds to dietary beta-hydroxy-beta-methylbutyrate similarly to that of young adults. J Nutr 2001;131:2049-52.
7. Gallagher PM, Carrithers JA, Godard MP, et al. Beta-hydroxy-beta-methylbutyrate ingestion, Part I: effects on strength and fat free mass. Med Sci Sports Exerc 2000;32:2109-15.
The ability of yohimbine, a chemical found in yohimbe bark, to stimulate the nervous system, 1, 2 and to promote the release of fat from fat cells,3, 4 has led to claims that it might help weight loss by raising metabolic rate, reducing appetite, or increase fat burning. Although a preliminary trial found yohimbine ineffective for weight loss, a double-blind study found that women taking 5 mg of yohimbine four times per day along with a weight-loss diet lost significantly more weight than those taking a placebo with the same diet after three weeks.5 However, a similar study using 18 mg per day of yohimbine for eight weeks reported no benefit to weight loss compared with a placebo.6 A double-blind study of men who were not dieting reported no effect of up to 43 mg per day of yohimbine on weight or body composition after six months.7 All of these studies used pure yohimbine; no study has tested the effects of yohimbe herb on weight loss.
1. Mosqueda-Garcia R, Fernandez-Violante R, Tank J, et al. Yohimbine in neurally mediated syncope. Pathophysiological implications. J Clin Invest 1998;102:1824-30.
2. Goldberg MR, Robertson D. Yohimbine: a pharmacological probe for the study of the alpha 2-adrenoceptor. Pharmacol Rev 1983;35:143-180
3. Galitzky J, Taouis M, Berlan M, et al. Alpha 2-antagonist compounds and lipid mobilization: evidence for a lipid mobilizing effect of oral yohimbine in healthy male volunteers. Eur J Clin Invest 1988;18:587-94.
4. Zahorska-Markiewicz B, Kucio C, Piskorska D. Adrenergic control of lipolysis and metabolic responses in obesity. Horm Metab Res 1986;18:693-7.
5. Kucio C, Jonderko K, Piskorska D. Does yohimbine act as a slimming drug? Isr J Med Sci 1991;27:550-6.
6. Berlin I, Crespo-Laumonnier B, Turpin G, Puech AJ. The alpha-2 adrenoceptor antagonist yohimbine does not facilitate weight loss but blocks adrenaline induced platelet aggregation in obese subjects. Therapie 1989;44:301 [letter].
7. Sax L. Yohimbine does not affect fat distribution in men. Int J Obes 1991;15:561-5.
1. Marquette CJ Jr. Effects of bulk producing tablets on hunger intensity in dieting patients. Obes Bariatr Med 1976;5:84-8.
2. Rossner S, von Zweigbergk D, Ohlin A, Ryttig K. Weight reduction with dietary fibre supplements. Acta Med Scand 1987;222:83-8.
3. Ryttig KR, Tellnes G, Haegh L, et al. A dietary fibre supplement and weight maintenance after weight reduction: a randomized, double-blind, placebo-controlled long-term trial. Int J Obes 1989;13:165-71.
4. Solum TT, Ryttig KR, Solum E, Larsen S. The influence of a high-fibre diet on body weight, serum lipids and blood pressure in slightly overweight persons. A randomized, double-blind, placebo-controlled investigation with diet and fibre tablets (DumoVital). Int J Obes 1987;11 Suppl 1:67-71.
5. Hylander B, Rössner S. Effects of dietary fiber intake before meals on weight loss and hunger in a weight-reducing club. Acta Med Scand 1983;213:217-20.
1. Hochstenbach-Waelen A, Veldhorst MA, Nieuwenhuizen AG, at al. Comparison of 2 diets with either 25% or 10% of energy as casein on energy expenditure, substrate balance, and appetite profile. Am J Clin Nutr 2009;89:831-8.
2. Veldhorst MA, Nieuwenhuizen AG, Hochstenbach-Waelen A, at al. Comparison of the effects of a high- and normal-casein breakfast on satiety, 'satiety' hormones, plasma amino acids and subsequent energy intake. Br J Nutr 2009;101:295-303.
3. Anderson JW, Fuller J, Patterson K, et al. Soy compared with casein meal replacement shakes with energy-restricted diets for obese women: randomized controlled trial. Metabolism 2007;56:280-8.
4. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Ann Nutr Metab 2000;44:21-9.
1. Yoshioka M, Doucet E, Drapeau V, et al. Combined effects of red pepper and caffeine consumption on 24 h energy balance in subjects given free access to foods. Br J Nutr 2001;85:203-11.
2. Yoshioka M, St-Pierre S, Drapeau V, et al. Effects of red pepper on appetite and energy intake. Br J Nutr 1999;82:115-23.
3. Yoshioka M, Doucet E, Drapeau V, et al. Combined effects of red pepper and caffeine consumption on 24 h energy balance in subjects given free access to foods. Br J Nutr 2001;85:203-11.
4. Yoshioka M, St-Pierre S, Suzuki M, Tremblay A. Effects of red pepper added to high-fat and high-carbohydrate meals on energy metabolism and substrate utilization in Japanese women. Br J Nutr 1998;80:503-10.
5. Yoshioka M, Lim K, Kikuzato S, et al. Effects of red-pepper diet on the energy metabolism in men. J Nutr Sci Vitaminol (Tokyo) 1995;41:647-56.
1. Biancardi G, Palmiero L, Ghirardi PE. Glucomannan in the treatment of overweight patients with osteoarthritis. Curr Ther Res 1989;46:908-12.
2. Vita PM, Restelli A, Caspani P, Klinger R. Chronic use of glucomannan in the dietary treatment of severe obesity. Minerva Med 1992;83:135-9 [in Italian].
3. Walsh DE, Yaghoubian V, Behforooz A. Effect of glucomannan on obese patients: a clinical study. Int J Obes 1984;8:289-93.
4. Livieri C, Novazi F, Lorini R. The use of highly purified glucomannan-based fibers in childhood obesity. Pediatr Med Chir 1992;14:195-8 [in Italian].
1. Koh EH, Lee WJ, Lee SA, et al. Effects of alpha-lipoic acid on body weight in obese subjects. Am J Med 2011;124:85.e1-85.e8.
2. Huerta AE, Navas-Carretero S, Prieto-Hontoria PL, et al. Effects of alpha-lipoic acid and eicosapentaenoic acid in overweight and obese women during weight loss. Obesity 2015;23:313–21.
Caution: Calcium supplements should be avoided by prostate cancer patients.
In a study of obese people consuming a low-calorie diet for 24 weeks, those receiving a calcium supplement (800 mg per day) lost significantly more weight than those given a placebo.1 Calcium was effective when provided either as a supplement, or in the form of dairy products. In a second study, however, the amount of weight loss resulting from calcium supplementation (1,000 mg per day) was small and not statistically significant.2 In that study, participants' typical diet contained more calcium than in the study in which calcium supplementation was more effective. Thus, it is possible that calcium supplementation enhances weight loss only when the diet is low in calcium.
1. Zemel MB, Thompson W, Milstead A, et al. Calcium and dairy acceleration of weight and fat loss during energy restriction in obese adults. Obes Res 2004;12:582–90.
2. Shapses SA, Heshka S, Heymsfield SB. Effect of calcium supplementation on weight and fat loss in women. J Clin Endocrinol Metab 2004;89:632–7.
Green tea extract rich in polyphenols (epigallocatechin gallate, or EGCG) may support a weight-loss program by increasing energy expenditure or by inhibiting the digestion of fat in the intestine.1 Healthy young men who took two green tea capsules (containing a total of 50 mg of caffeine and 90 mg of EGCG) three times a day burned significantly more calories and oxidized significantly more fat than those who took caffeine alone or a placebo. In a preliminary study of moderately obese individuals, administration of a specific green tea extract (AR25) resulted in a 4.6% reduction in average body weight after 12 weeks. The amount of green tea extract used in this study supplied daily 270 mg of EGCG and 150 mg of caffeine.
While caffeine is known to stimulate metabolism, it appears that other substances besides caffeine were responsible for at least part of the weight loss. Although the extract produced few side effects, one individual developed abnormal liver function tests during the study. In another study, consuming approximately 12 ounces of oolong tea (a semifermented version of green tea) daily for 12 weeks reduced waist circumference and the amount of body fat in a group of normal-weight to overweight men. However, in another study, 300 mg per day of EGCG was no more effective than a placebo for promoting weight loss in overweight postmenopausal women.2 Additional studies are needed to confirm the safety and effectiveness of green tea extracts for promoting weight loss.
The relationship between iodine and thyroid function is complex. Iodine is required by the body to form thyroid hormone, and iodine deficiency can lead to goiter and hypothyroidism.1 Severe and prolonged iodine deficiency can potentially lead to serious types of hypothyroidism, such as myxedema or cretinism. It is estimated that one and a half billion people living in 118 countries around the world are at risk for developing iodine deficiency.2
Today, most cases of iodine deficiency occur in developing nations. In industrialized countries where iodized salt is used, iodine deficiency has become extremely rare. On the other hand, iodine toxicity has become a concern in some of these countries.3 Excessive iodine intake can result in either hypothyroidism4 or hyperthyroidism (overactive thyroid).5 Sources of iodine include foods (iodized salt, milk, water, seaweed, ground beef), dietary supplements (multiple vitamin-mineral formulas, seaweed extracts), drugs (potassium iodide, amiodarone, topical antiseptics), and iodine-containing solutions used in certain laboratory tests. Many nutritional supplements contain 150 mcg of iodine. While that amount of iodine should prevent a deficiency, it is not clear whether supplementing with iodine is necessary or desirable for most people. Those wishing to take a nutritional supplement containing iodine should consult a doctor.
1. Thilly CH, Swennen B, Bourdoux P, et al. The epidemiology of iodine-deficiency disorders in relation to goitrogenic factors and thyroid-stimulating-hormone regulation. Am J Clin Nutr 1993;57(2 Suppl):267S-70S.
2. Delange F. Risks and benefits of iodine supplementation. Lancet 1998;351:923-4.
3. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol Metab 1991;73:213-5.
4. Chow CC, Phillips DIW, Lazarus JH, Parkes AB. Effect of low dose iodide supplementation on thyroid function in potentially susceptible subjects: are dietary iodide levels in Britain acceptable? Clin Endocrinol 1991;34:413-6.
5. Stewart JC, Vidor GI. Thyrotoxicosis induced by iodine contamination of food: a common unrecognized condition? Br Med J 1976;1:372-5.
1. Lowenstein JM. Effect of (-)-hydroxycitrate on fatty acid synthesis by rat liver in vivo. J Biol Chem 1971;246:629-32.
2. Triscari J, Sullivan AC. Comparative effects of (-)-hydroxycitrate and ( )-allo-hydroxycitrate on acetyl CoA carboxylase and fatty acid and cholesterol synthesis in vivo. Lipids 1977;12:357-63.
3. Cheema-Dhadli S, Harlperin ML, Leznoff CC. Inhibition of enzymes which interact with citrate by (-)hydroxycitrate and 1,2,3,-tricarboxybenzene. Eur J Biochem 1973;38:98-102.
4. Sullivan AC, Hamilton JG, Miller ON, et al. Inhibition of lipogenesis in rat liver by (-)-hydroxycitrate. Arch Biochem Biophys 1972;150:183-90.
5. Greenwood MRC, Cleary MP, Gruen R, et al. Effect of (-)-hydroxycitrate on development of obesity in the Zucker obese rat. Am J Physiol 1981;240:E72-8.
6. Sullivan AC, Triscari J. Metabolic regulation as a control for lipid disorders. Am J Clin Nutr 1977;30:767-76.
7. Sullivan AC, Triscari J, Hamilton JG, et al. Effect of (-)-hydroxycitrate upon the accumulation of lipid in the rat: I. Lipogenesis. Lipids 1974;9:121-8.
8. Sullivan AC, Triscari J, Hamilton JG, et al. Effect of(-)-hydroxycitrate upon the accumulation of lipid in the rat: II. Appetite. Lipids1974;9:129-34.
9. Heymsfield SB, Allison DB, Vasselli JR, et al. Garcinia cambogia (hydroxycitricacid) as a potential antiobesity agent: a randomized controlled trial. JAMA1998;280:1596-600.
10. Martinet A, Hostettmann K, Schultz Y. Thermogenic effects of commercially available plant preparations aimed at treating human obesity. Phytomedicine 1999;6:231-8.
11. Mattes RD, Bormann L. Effects of (-)-hydroxycitric acid on appetitive variables. Physiol Behav 2000;71:87-94.
1. Marshall JJ, Lauda CM. Purification and properties of phaseolamin, an inhibitor of alpha-amylase, from the kidney bean, Phaseolus vulgaris. J Biol Chem 1975;250:8030-7.
2. Choudhury A, Maeda K, Murayama R, DiMagno EP. Character of a wheat amylase inhibitor preparation and effects on fasting human pancreaticobiliary secretions and hormones. Gastroenterology 1996;111:1313-20.
3. Bo-Linn GW, Santa Ana CA, Morawski SG, Fordtran JS. Starch blockers—their effect on calorie absorption from a high-starch meal. N Engl J Med 1982;307:1413-6.
4. Hollenbeck CB, Coulston AM, Quan R, et al. Effects of a commercial starch blocker preparation on carbohydrate digestion and absorption: in vivo and in vitro studies. Am J Clin Nutr 1983;38:498-503.
5. Garrow JS, Scott PF, Heels S, et al. A study of 'starch blockers' in man using 13C-enriched starch as a tracer. Hum Nutr Clin Nutr 1983;37:301-5.
6. Carlson GL, Li BU, Bass P, Olsen WA. A bean alpha-amylase inhibitor formulation (starch blocker) is ineffective in man. Science 1983;219:393-5.
7. Brugge WR, Rosenfeld MS. Impairment of starch absorption by a potent amylase inhibitor. Am J Gastroenterol 1987;82:718-22.
8. Boivin M, Zinsmeister AR, Go VL, DiMagno EP. Effect of a purified amylase inhibitor on carbohydrate metabolism after a mixed meal in healthy humans. Mayo Clin Proc 1987;62:249-55.
9. Layer P, Carlson GL, DiMagno EP. Partially purified white bean amylase inhibitor reduces starch digestion in vitro and inactivates intraduodenal amylase in humans. Gastroenterology 1985;88:1895-902.
One double-blind trial found 100 mg per day of DHEA was effective for decreasing body fat in older men,1 and another double-blind trial found 1,600 mg per day decreased body fat and increased muscle mass in younger men,2. However, DHEA has not been effective for improving body composition in women or in other studies of men.3, 4, 5, 6, 7, 8, 9, 10
1. Morales AJ, Haubrich RH, Hwang JY, et al. The effect of six months treatment with a 100 mg daily dose of dehydroepiandrosterone (DHEA) on circulating sex steroids, body composition and muscle strength in age-advanced men and women. Clin Endocrinol (Oxf) 1998;49:421-32.
2. Nestler JE, Barlascini CO, Clore JN, Blackard WG. Dehydroepiandrosterone reduces serum low density lipoprotein levels and body fat but does not alter insulin sensitivity in normal men. J Clin Endocrinol Metab 1988;66:57-61.
3. Percheron G, Hogrel JY, Denot-Ledunois S, et al. Effect of 1-year oral administration of dehydroepiandrosterone to 60- to 80-year-old individuals on muscle function and cross-sectional area: a double-blind placebo-controlled trial. Arch Intern Med 2003;163:720-7.
4. Wallace MB, Lim J, Cutler A, Bucci L. Effects of dehydroepiandrosterone vs androstenedione supplementation in men. Med Sci Sports Exerc 1999;31:1788-92.
5. Brown GA, Vukovich MD, Sharp RL, et al. Effect of oral DHEA on serum testosterone and adaptations to resistance training in young men. J Appl Physiol 1999;87:2274-83.
6. Morales AJ, Haubrich RH, Hwang JY, et al. The effect of six months treatment with a 100 mg daily dose of dehydroepiandrosterone (DHEA) on circulating sex steroids, body composition and muscle strength in age-advanced men and women. Clin Endocrinol (Oxf) 1998;49:421-32.
7. Vogiatzi MG, Boeck MA, Vlachopapadopoulou E, et al. Dehydroepiandrosterone in morbidly obese adolescents: effects on weight, body composition, lipids, and insulin resistance. Metabolism 1996;45:1011-5.
8. Morales AJ, Nolan JJ, Nelson JC, Yen SS. Effects of replacement dose of dehydroepiandrosterone in men and women of advancing age. J Clin Endocrinol Metab 1994;78:1360-7.
9. Mortola JF, Yen SS. The effects of oral dehydroepiandrosterone on endocrine-metabolic parameters in postmenopausal women. J Clin Endocrinol Metab 1990;71:696-704.
10. Usiskin KS, Butterworth S, Clore JN, et al. Lack of effect of dehydroepiandrosterone in obese men. Int J Obes 1990;14:457-63.
High-protein diets have been shown to help prevent and treat obesity.1, 2 Researchers have found in a number of studies that, compared to eating carbohydrates in the morning, eating an egg breakfast is associated with appetite reduction and reduced calorie intake that could lead to weight loss in overweight and obese people.3, 4, 5, 6, 7 A mid-day egg meal has also been found to induce more of a sense of fullness than a carbohydrate-rich meal.8 How egg protein compares to whole eggs and to other protein supplements for reducing appetite and calorie consumption is not yet known.
1. Johansson K, Neovius M, Hemmingsson E. Effects of anti-obesity drugs, diet, and exercise on weight-loss maintenance after a very-low-calorie diet or low-calorie diet: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr 2014;99:14-23. doi: 10.3945/ajcn.113.070052. Epub 2013 Oct 30. [review]
2. Gilbert J, Bendsen N, Tremblay A, Astrup A. Effect of proteins from different sources on body composition. Nutr Metab Cardiovasc Dis 2011;21 Suppl 2:B16-31. doi: 10.1016/j.numecd.2010.12.008.
3. Wang S, Yang L, Lu J, Mu Y. High-protein breakfast promotes weight loss by suppressing subsequent food intake and regulating appetite hormones in obese Chinese adolescents. Horm Res Paediatr 2014 Jun 11. [Epub ahead of print]
4. Vander Wal J, Marth J, Khosla P, et al. Short-term effect of eggs on satiety in overweight and obese subjects. J Am Coll Nutr 2005;24:510-5.
5. Bayham B, Greenway F, Johnson W, Dhurandhar N. A randomized trial to manipulate the quality instead of quantity of dietary proteins to influence the markers of satiety. J Diabetes Complications 2014;28:547-52. doi: 10.1016/j.jdiacomp.2014.02.002.
6. Fallaize R, Wilson L, Gray J, et al. Variation in the effects of three different breakfast meals on subjective satiety and subsequent intake of energy at lunch and evening meal. Eur J Nutr 2013;52:1353-9. doi: 10.1007/s00394-012-0444-z.
7. Ratliff J, Leite J, de Ogburn R, et al. Consuming eggs for breakfast influences plasma glucose and ghrelin, while reducing energy intake during the next 24 hours in adult men. Nutr Res 2010;30:96-103. doi: 10.1016/j.nutres.2010.01.002.
8. Pombo-Rodrigues S, Calame W, Re R. The effects of consuming eggs for lunch on satiety and subsequent food intake. Int J Food Sci Nutr 2011;62:593-9. doi: 10.3109/09637486.2011.566212.
1. Anderson RA. Effects of chromium on body composition and weight loss. Nutr Rev 1998;56:266-70.
2. Crawford V, Scheckenbach R, Preuss HG. Effects of niacin-bound chromium supplementation on body composition in overweight African-American women. Diabetes Obes Metab 1999;1:331-7.
3. Bahadori B, Wallner S, Schneider H, et al. Effect of chromium yeast and chromium picolinate on body composition of obese, non-diabetic patients during and after a formula diet. Acta Med Austriaca 1997;24:185-7
4. Trent LK, Thieding-Cancel D. Effects of chromium picolinate on body composition. J Sports Med Phys Fitness 1995;35:273-80
5. Volpe SL, Huang HW, Larpadisorn K, Lesser II. Effect of chromium supplementation and exercise on body composition, resting metabolic rate and selected biochemical parameters in moderately obese women following an exercise program. J Am Coll Nutr 2001;20:293-306.
6. Pittler MH, Stevinson C, Ernst E. Chromium picolinate for reducing body weight: meta-analysis of randomized trials. Int J Obes Relat Metab Disord 2003;27:522-9.
Animal research and preliminary human reports suggest that serotonin precursors such as L-tryptophan or 5-HTP (5-hydroxytryptophan) might help control appetite and promote weight loss.1, 2 In a controlled study, increasing L-tryptophan supplementation one hour before a meal from 1 gram to 2 grams to three grams resulted in progressively fewer calories and carbohydrates being consumed during the meal at the higher L-tryptophan dosages.3 While this effect might lead to weight loss over time, a small double-blind trial did not find a significant benefit from taking 1 gram of L-tryptophan before each meal as part of a six-week weight loss program.4 Weight-loss diets result in lower L-tryptophan and serotonin levels in women,5 which could theoretically trigger cravings and make dieting more difficult.6 More research is needed to determine whether L-tryptophan might improve the results of a long-term weight loss diet.
1. Morris P, Li ET, MacMillan ML, Anderson GH. Food intake and selection after peripheral tryptophan. Physiol Behav 1987;40:155-63.
2. Caston JC. Clinical applications of l-tryptophan in the treatment of obesity and depression. Adv Ther 1987;4:78-83.
3. Cavaliere H, Medeiros-Neto G. The anorectic effect of increasing doses of L-tryptophan in obese patients. Eat Weight Disord 1997;2:211-5.
4. Strain GW, Strain JJ, Zumoff B. L-tryptophan does not increase weight loss in carbohydrate-craving obese subjects. Int J Obes 1985;9:375-80.
5. Anderson IM, Parry-Billings M, Newsholme EA, et al. Dieting reduces plasma tryptophan and alters brain 5-HT function in women. Psychol Med 1990;20:785-91.
6. Wurtman JJ. The involvement of brain serotonin in excessive carbohydrate snacking by obese carbohydrate cravers. J Am Diet Assoc 1984;84:1004-7.
1. Cho AS, Jeon SM, Kim MJ, et al. Chlorogenic acid exhibits anti-obesity property and improves lipid metabolism in high-fat diet-induced-obese mice. Food Chem Toxicol 2010;48:937-43.
2. Shimoda H, Seki E, Aitani M. Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice. BMC Complement Altern Med 2006;6:9.
3. Bakuradze T, Boehm N, Janzowski C, et al. Antioxidant-rich coffee reduces DNA damage, elevates glutathione status and contributes to weight control: results from an intervention study. Mol Nutr Food Res 2011;55:793-7
4. Thom E. The effect of chlorogenic acid enriched coffee on glucose absorption in healthy volunteers and its effect on body mass when used long-term in overweight and obese people J Int Med Res 2007;35:900-8.
5. Dellalibera O. Lemaire B, Lafay S. Svetol, green coffee extract, induces weight loss and increases the lean to fat mass ratio in volunteers with overweight problem. Phytotherapie 2006;4:194-7.
1. Bhathena SJ, Velasquez MT. Beneficial role of dietary phytoestrogens in obesity and diabetes. Am J Clin Nutr 2002;76:1191-201 [review].
2. Allison DB, Gadbury G, Schwartz LG, et al. A novel soy-based meal replacement formula for weight loss among obese individuals: a randomized controlled clinical trial. Eur J Clin Nutr 2003;57:514-22.
3. Bosello O, Cominancini L, Zocca I, et al. Short- and long-term effects of hypocaloric diets containing proteins of different sources on plasma lipids and apoproteins of obese subjects. Ann Nutr Metab 1988; 32:206-14.
4. Yamashita T, Sasahara T, Pomeroy SE, et al. Arterial compliance, blood pressure, plasma leptin, and plasma lipids in women are improved with weight reduction equally with a meat-based diet and a plant-based diet. Metabolism 1998;47:1308-14.
5. Jenkins DJ, Wolever TM, Spiller G, et al. Hypocholesterolemic effect of vegetable protein in a hypocaloric diet. Atherosclerosis 1989;78:99-107.
1. Maeda H, Hosokawa M, Sashima T, et al. Effect of medium-chain triacylglycerols on anti-obesity effect of fucoxanthin. J Oleo Sci 2007;56:615-21.
2. Maeda H, Hosokawa M, Sashima T, Miyashita K. Dietary combination of fucoxanthin and fish oil attenuates the weight gain of white adipose tissue and decreases blood glucose in obese/diabetic KK-Ay mice. J Agric Food Chem 2007;55:7701-6.
3. Maeda H, Hosokawa M, Sashima T, et al. Fucoxanthin from edible seaweed, Undaria pinnatifida, shows antiobesity effect through UCP1 expression in white adipose tissues. Biochem Biophys Res Commun 2005;332:392-7.
4. Asai A, Yonekura L, Nagao A. Low bioavailability of dietary epoxyxanthophylls in humans. Br J Nutr 2008 Jan 11;:1-5 [Epub ahead of print].
Researchers have found that a high-protein diet might help reduce appetite and improve blood glucose control,1 help people lose weight and keep it off,2 and help preserve muscle mass during weight loss.3 Although most hemp protein supplements have less protein than other protein supplements, they are higher in fiber, which has also been shown to reduce appetite, improve glucose metabolism, and contribute to weight management.4 Whether hemp protein has real benefits or drawbacks compared to other sources of protein for people trying to lose weight is not known.
1. Potier M, Darcel N, Tome D. Protein, amino acids and the control of food intake. Curr Opin Clin Nutr Metab Care 2009;12:54-8. doi: 10.1097/MCO.0b013e32831b9e01. [review]
2. Johansson K, Neovius M, Hemmingsson E. Effects of anti-obesity drugs, diet, and exercise on weight-loss maintenance after a very-low-calorie diet or low-calorie diet: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr 2014;99:14-23. doi: 10.3945/ajcn.113.070052. Epub 2013 Oct 30. [review]
3. Devkota S, Layman D. Protein metabolic roles in treatment of obesity. Curr Opin Clin Nutr Metab Care 2010;13:403-7. doi: 10.1097/MCO.0b013e32833a7737. [review]
4. Chutkan R, Fahey G, Wright W, McRorie J. Viscous versus nonviscous soluble fiber supplements: mechanisms and evidence for fiber-specific health benefits. J Am Acad Nurse Pract 2012;24:476-87. doi: 10.1111/j.1745-7599.2012.00758.x. [review]
Guar gum, another type of fiber supplement, has not been effective in controlled studies for weight loss or weight maintenance.1, 2, 3
1. Kovacs EM, Westerterp-Plantenga MS, Saris WH, et al. The effect of addition of modified guar gum to a low-energy semisolid meal on appetite and body weight loss. Int J Obes Relat Metab Disord 2001;25:307-15.
2. Beattie VA, Edwards CA, Hosker JP, et al. Does adding fibre to a low energy, high carbohydrate, low fat diet confer any benefit to the management of newly diagnosed overweight type II diabetics? Br Med J (Clin Res Ed) 1988;296:1147-9.
3. Pasman WJ, Westerterp-Plantenga MS, Muls E, et al. The effectiveness of long-term fibre supplementation on weight maintenance in weight-reduced women. Int J Obes Relat Metab Disord 1997;21:548-55.
1. Bianchi G, Marzocchi R, Agostini F, Marchesini G. Update on nutritional supplementation with branched-chain amino acids. Curr Opin Clin Nutr Metab Care 2005;8:83-7. [review]
2. Diepvens K, Haberer D, Westerterp-Plantenga M. Different proteins and biopeptides differently affect satiety and anorexigenic/orexigenic hormones in healthy humans. Int J Obes 2008;32:510-8. doi: 10.1038/sj.ijo.0803758. Epub 2007 Nov 27.
3. Abou-Samra R, Keersmaekers L, Brienza D, et al. Effect of different protein sources on satiation and short-term satiety when consumed as a starter. Nutr J 2011;10:139. doi: 10.1186/1475-2891-10-139.
1. Colker CM, Kalman DS, Torina GC, et al. Effects of Citrus aurantium extract, caffeine, and St. John's wort on body fat, lipid levels, and mood states in overweight adults. Curr Ther Res 1999;60:145-53.
2. Calapai G, Firenzuoli F, Saitta A, et al. Antiobesity and cardiovascular toxic effects of Citrus aurantium extracts in the rat: A preliminary report. Fitoterapia 1999;70:586-92.
1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 293-4.
2. Astrup A, Breum L, Toubro S, et al. The effect and safety of an ephedrine/caffeine compound compared to ephedrine, caffeine and placebo in obese subjects on an energy restricted diet. A double blind trial. Int J Obes Relat Metab Disord 1992;16:269-77.
Read details for informationOne small, double-blind study in humans found that hoodia latex and inner plant can significantly reduce food intake. However, in another double-blind study, hoodia extract taken twice a day for 15 days had no effect on caloric intake or body weight compared with a placebo. Adverse effects of hoodia included nausea, vomiting, and increases in blood pressure and bilirubin levels (a possible indicator of liver stress).1 Available products are of unknown quality and much more work remains to be done to determine if hoodia has a role in treating obesity.2
1. Blom WA, Abrahamse SL, Bradford R, et al. Effects of 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 2011;94:1171-81.
2. Phytopharm. Successful completion of proof of principle clinical study of P57 for obesity [press release] 2001 Dec 5 [cited 2005 Sep 20]. Available from URL: http://www.phytopharm.co.uk/press/P57 Third Stage final.htm.
1. He Z-Q, Phone ZS. Body weight reductionin adolescents by a combination of measures including using L-carnitine. Acta NutrimentaSinica 1997;19.
2. VillaniRG, Gannon J, Self M, Rich PA. L-Carnitine supplementation combined with aerobictraining does not promote weight loss in moderately obese women. Int J SportNutrExerc Metab 2000;10:199-207.
Whey protein may aid weight loss due to its effect on appetite. In a preliminary study, people were given 48 grams of either whey protein or milk protein (casein). Whey consumption resulted in more hunger satisfaction and reduced the amount of food eaten 90 minutes later compared with casein consumption.1 However, a double-blind study found that men taking 1.5 grams per 2.2 lbs body weight per day of whey protein for 12 weeks along with a low-calorie diet and a strength training exercise program lost the same amount of weight and body fat as did a control group that followed a similar program, but took a casein supplement instead of whey protein.2
1. Hall WL, Millward DJ, Long SJ, Morgan LM. Casein and whey exert different effects on plasma amino acid profiles, gastrointestinal hormone secretion and appetite. Br J Nutr 2003;89:239-48.
2. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Ann Nutr Metab 2000;44:21-9.
Manufacturers of relora, a product derived from Magnolia officinalis and Phellodendron amurense bark, claim that the extract helps balance hormones such as cortisol, which are associated with weight gain. Healthnotes has not seen published research demonstrating that relora promotes weight loss.
Laboratory animals with severe, experimentally induced zinc deficiency developed hypothyroidism, whereas moderate zinc deficiency did not affect thyroid function.1 In a small study of healthy people, thyroid hormone (thyroxine) levels tended to be lower in those with lower blood levels of zinc. In people with low zinc, supplementing with zinc increased thyroxine levels.2 One case has been reported of a woman with severe zinc deficiency (caused by the combination of alcoholism and malabsorption) who developed hypothyroidism that was corrected by supplementing with zinc.3 Although the typical Western diet is marginally low in zinc,4 additional research is needed to determine whether zinc supplementation would be effective for preventing or correcting hypothyroidism.
1. Fujimoto S, Indo Y, Higashi A, et al. Conversion of thyroxine into tri-iodothyronine in zinc deficient rat liver. J Pediatr Gastroenterol Nutr 1986;5:799-805.
2. Hartoma TR, Sotaniemi EA, Maattanen J. Effect of zinc on some biochemical indices of metabolism. Nutr Metab 1979;23:294-300.
3. Weismann K, Roed-Petersen J, Hjorth N, Kopp H. Chronic zinc deficiency syndrome in a beer drinker with a Billroth II resection. Int J Dermatol 1976;15:757-61.
4. Wolf WR, Holden J, Greene FE. Daily intake of zinc and copper from self selected diets. Fed Proc 1977;36:1175.
Selenium plays a role in thyroid hormone metabolism. Severe selenium deficiency has been implicated as a possible cause of goiter.1 Two months of selenium supplementation in people who were deficient in both selenium and iodine was shown to induce a dramatic fall of the already impaired thyroid function in clinically hypothyroid subjects.2 Researchers have suggested that people who are deficient in both selenium and iodine should not take selenium supplements without first receiving iodine or thyroid hormone supplementation.3 There is no research demonstrating that selenium supplementation helps people with hypothyroidism who are not selenium-deficient.
1. Thilly CH, Swennen B, Bourdoux P, et al. The epidemiology of iodine-deficiency disorders in relation to goitrogenic factors and thyroid-stimulating-hormone regulation. Am J Clin Nutr 1993;57(2 Suppl):267S-70S.
2. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol Metab 1991;73:213-5.
3. Vanderpas JB, Contempre B, Duale NL, et al. Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects. Am J Clin Nutr 1993 Feb;57(2 Suppl):271S-275S [review].
Desiccated thyroid, also called thyroid extract (e.g., Armour Thyroid), is used by some doctors as an alternative to synthetic thyroid hormones (such as thyroxine [Synthroid or other brand names]) for people with hypothyroidism. Thyroid extract contains two biologically active hormones (thyroxine and triiodothyronine), whereas the most commonly prescribed thyroid-hormone preparations contain only thyroxine. One study has shown that the combination of the two hormones contained in desiccated thyroid is more effective than thyroxine alone for those with hypothyroidism.1 One doctor reported that thyroid extract worked better than standard thyroid preparations for many of his patients with hypothyroidism.2 Glandular thyroid products, which are available from health food stores, have had most of the thyroid hormone removed and would therefore not be expected to be effective for people with hypothyroidism. Intact desiccated thyroid is available only by prescription. Hypothyroidism sufferers who want to use desiccated thyroid must first consult with a physician.
People with hypothyroidism have been shown to have an impaired ability to convert beta-carotene to vitamin A.1, 2 For this reason, some doctors suggest taking supplemental vitamin A (approximately 5,000–10,000 IU per day) if they are not consuming adequate amounts in their diet.
Preliminary data indicate that vitamin B3 (niacin) supplementation may decrease thyroid hormone levels. In one small study, 2.6 grams of niacin per day helped lower blood fat levels.1 After a year or more, thyroid hormone levels had fallen significantly in each person, although none experienced symptoms of hypothyroidism. In another case report, thyroid hormone levels decreased in two people who were taking niacin for high cholesterol and triglycerides; one of these two was diagnosed with hypothyroidism.2 When the niacin was discontinued for one month, thyroid hormone levels returned to normal.
1. Shakir KMM, Kroll S, Aprill BS, et al. Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state. Mayo Clin Proc 1995;70:556-8.
2. O'Brien T, Silverberg JD, Nguyen TT. Nicotinic acid-induced toxicity associated with cytopenia and decreased levels of thyroxine-binding globulin. Mayo Clin Proc 1992;67:465-8.
Bladderwrack (Fucus vesiculosus) is a type of brown seaweed that contains variable amounts of iodine.1 Hypothyroidism due to insufficient intake of iodine may possibly improve with bladderwrack supplementation, though human studies have not confirmed this.
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The information presented by Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2018.