WeightLossSupplements_TapeMeasure

Part 2 of a 4-part series on metabolism and weight loss.

Which supplements actually work for weight loss?

Wouldn’t it be great if there was a magic pill that could help you achieve your goal weight without having to change anything else? If you check with the average consumer I can pretty much bet they have tried at least one of the thousands of weight loss products out there. The marketing it just too good with all of those outrageous “before” and “after” photos and catch phrases like, “Lose weight and feel great…no work required.” So, how does the research on these products actually hold up to the claims?

Let’s dive deep into this topic by exploring a few of the more popular items out there including medium chain triglycerides (MCTs), green tea extract, capsaicin, calcium, and a few others. 

  1. MCTs:

What is it?

  • MCTs are fatty acids made up of 8-12 carbon atoms and include caprylic acid, capric acid, lauric acid
    • Food sources: coconut oil (65% MCTs), palm kernel oil, coconut meat
    • Supplements and isolated MCT-oil are also available
  • They may reduce weight by increasing thermogenesis and improving satiety
  • There is a faster rate of oxidation of MCTs compared to long-chain triglycerides (LCTs) due to smaller fatty acid chain length leading to greater energy expenditure

What does the research say?

  • A meta-analysis assessed 13 randomized controlled trials >3 weeks duration in healthy adults (Mumme, 2014)
    • Effective dose was not determined
    • Studies >12 weeks produced more weight loss than less than studies <12 weeks
    • More weight loss with MCT dose <8% energy compared to >16%
    • More weight loss in commercially biased trials
    • On average, there is a small reduction in body weight of 0.51kg (1.1lb) over ~10 weeks (dose 2g to 54g per day) by using MCTs in replacement of LCTs
    • Further research is required

My conclusion? 

  • MCT food, isolated-oil, and supplements are safe to use in small to moderate doses, but may not produce significant effects on weight loss. If you do start using MCT-oil, make sure it is in replacement of other fat sources if you are trying to achieve weight loss. I would not recommend spending money of MCT supplements, but just try to incorporate some coconut oil in your cooking.

2. Green Tea Extract (EGCG):

What is it?

  • EGCG stands for epigallocatechin gallate and is a constituent of the green tea leaf
  • It is typically extracted and consumed in supplement formulations in varying concentrations 
  • EGCG has a potent antioxidant effect in the body and has been researched for its numerous health benefits that will not be discussed in this article. However, it has been thought to help improve metabolism and weight loss. 

What does the research say?

  • Meta-analysis showed conflicting evidence on EGCG (standardized to 25%) at 576-714mg/day with caffeine (Hursel, 2009)
    • Modest improvement in BMI, body weight and waist circumference
    • Not effective without caffeine, and caffeine alone is not effective for weight loss
    • Mildly effective for specific populations
      • More effective for weight loss in Asians than Caucasians
      • More effective for those who do not regularly consume caffeine than those with regular caffeine use 

My conclusion? 

  • EGCG has many known health benefits and is very safe for the general population to use. In terms of weight loss, EGCG may have a mild impact in formulations that include caffeine. I believe it may be best to drink freshly brewed caffeinated green tea throughout the day. It offers the antioxidant health benefits, the hydration benefit, help reduce overall calorie intake and assist with weight loss. 

3. Capsaicin:

What is it?

  • Hot red peppers contain capsaicinoids, one of the primary types being capsaicin. Sweet red peppers contain capsiate (CH-19), which has similar effects of capsaicin without the “burning mouth” sensation. 
  • Both capsaicin and capsiate bind to the TRPV1 receptor in the gut, absorb into circulation, and stimulate the release of catecholamines. This increases sympathetic nervous system activity
  • May help suppress appetite by reducing ghrelin concentrations
  • Capsaicin and capsiate stimulate thermogenesis by increasing brown adipose tissue (BAT) and enhancing core and skin temperatures
  • May increase fat oxidation

What does the research say?

  • A meta-analysis reviewed 25 human studies for thermogenic and appetitive outcomes in humans with use of capsaicin and capsiate (Ludy, 2012)
    • Magnitude of their effect is small and long-term outcomes are unknown
    • ~1lb weight loss over 6.5 years in an average weight, middle aged man would be expected based on findings that they promote 10-50kcal negative energy balance 
    • Regular users may become desensitized with long-term use

My conclusion? 

  • Do not waste your money on capsaicin supplements, but rather incorporate peppers and capsaicin-containing foods (hot sauce, red pepper flakes, cayenne pepper, etc.) into your diet. The overall weight loss impact is extremely mild. 

4. Calcium:

What is it?

  • A vital mineral important for various functions throughout the body. It is important for building strong bones and teeth, muscle contraction, and nerve function. 
  • Calcium is primarily obtained through dairy foods, and it is also found in various plant foods including nuts, seeds, and leafy greens
  • Calcium has been studied in weight loss due to its ability to increase fecal fat excretion and improve insulin sensitivity

What does the research say?

  • Meta-analysis of 41 studies met inclusion criteria (calcium and/or dairy food intake consumed or >12 weeks, >300mg calcium/d) (Booth, 2015)
    • Calcium supplementation did not significantly affect body weight or body fat
    • Consumption of 3 servings of reduced fat dairy foods in conjunction with an energy-restricted diet results in more fat loss over a short time frame (<6 months)
      • This may be due to improved appetite control or the protein found in dairy foods increasing satiety and improving maintenance of lean muscle mass 

My conclusion? 

  • If you do not have a dairy allergy or sensitivity, consider eating low fat dairy products. You may eat whey protein shakes, cheese, milk, and yogurt/kefir as healthy options. Do not overload on calcium supplements as they can have many harmful effects if used in excess and do not seem to support weight loss. 

5. Others

Green Coffee Extract (3 trials reviewed) (Onakpoya, 2010)

Conclusion:

  • trials had a high risk of bias
  • significant but modest difference in body weight compared to placebo
  • all studies of poor quality

White Kidney Bean Extract, Phaseolus vulgaris (6 trials reviewed) (Onakpoya, 2011)

Conclusion:

  • all studies of poor quality
  • non-significant difference in weight loss but statistically significant reduction in body fat over placebo
  • larger and more rigorous trials are needed

Conjugated Linoleic Acid (CLA)

Conclusions:

  • mostly in vivo and in vitro studies
  • limited and inconclusive evidence supporting their role in humans for weight and fat loss

In conclusion, there is no magic pill for losing weight. All of these products must be used in conjunction with a healthy eating and exercise plan in order to see even mild results. It is probably best to focus on food sources of these products in order to save money and account for the possible synergistic effect of certain nutrients when consumed in foods. 

Stay tuned for Part III of this 4-part series on metabolism and weight management where I’ll review the effectiveness of popular fitness and lifestyle strategies. 

References:
  1. Obakpoya I, et al. The Efficiacy of Phaseolus Vulgaris as a Weight-Loss Supplement: A Systemic Review and Meta-Analysis of Randomised Clinical Trials. British Journal of Nutrition. 2001;106:196-202.
  2. Onakpoya I, et al. The Use of Green Coffee Extract as a Weight Loss Supplement: A Systemic Review and Meta-Analysis of Randomised Clinical Trials. Gastroenterology Research and Practice. 2010;2011:6 pages.
  3. Zemel MB, et al. Calcium and Dairy Acceleration of Weight and Fat Loss During Energy Restriction in Obese Adults. Obesity Research. 2004;12(4):582-590.
  4. Booth AO, et al. Effect of Increasing Dietary Calcium Through Supplements and Dairy Food on Body Weight and Body Composition: A Meta-Analysis of Randomised Controlled Trials. British Journal of Nutrition. 2015;114:1013-1025.
  5. Hursel R, et al. The Effects of Green Tea on Weight Loss and Weight Maintenance: A Meta-Analysis. International Journal of Obesity. 2009;33:956-961.
  6. Matsumoto T, et al. Effects of Capsaicin-containing Yellow Curry Sauce on Sympathetic Nervous System Activity and Diet-induced Thermogenesis in Lean and Obese Young Women. J Nutr Sci Vitaminol. 2000;46:309-315.
  7. Ludy MJ, et al. The Effects of Capsaicin and Capsiate on Energy Balance: A Critical Review and Meta-Analysis of Studies in Humans. Chem Senses. 2012;37:103-121.
  8. St-Onge MP and Jones PJ. Physiological Effects of Medium-Chain Triglycerides: Potential Agents in the Prevention of Obesity. J Nutr. 2002;132:329-332.
  9. Mumme K and Stonehouse W. Effects of Medium-Chain Triglycerides on Weight Loss and Body Composition: A Meta-Analysis of Randomized Controlled Trials. J Acad Nutr Diet. 2015;115:249-263.