Medium Chain Triglycerides and Weight Loss

Submitted by: Amy Sercel MS RD CD

Edited by: Marcia Bristow MS RDN CSSD CD

One of the first weight loss recommendations you’ll usually hear is to eat less fat, so it might come as a surprise that some people actually add a fat to their diet to promote weight loss.  The fat they’re adding is manufactured from coconut and palm kernel oils and contains only medium chain triglycerides (MCTs).  MCTs are saturated fats that have a different chemical structure than other types of fat.  All fat molecules, or triglycerides, are made up a glycerol molecule connected to three chains of carbon atoms.  The fats most commonly eaten in the United States are long chain triglycerides (LCTs) with chains that are about 12-18 carbons long.  The carbon chains in MCTs are about half as long, containing between 6 and 10 carbons.¹

When you eat LCTs they’re absorbed into your intestinal cells, then transported through your bloodstream to your tissue where they’ll be stored or used for energy.  Since MCTs are smaller, they’re absorbed more easily than LCTs.  After absorption, they go directly to your liver and are less likely to be deposited in fat cells throughout your body.^2,3 Researchers also believe that digesting MCTs may use more calories than other types of fat, so eating them could slightly increase the number of calories you burn every day.  People have also suggested that MCTs can promote satiety, so you will stay full for longer and eat less later on in the day.^1–3

Studies researching MCTs and weight loss have had mixed results.  One systematic review found that people using MCTs lost an average of about 1.12 pounds more than the control groups over 10 weeks.  Participants lost the most weight when they ate between 4 and 10 grams of MCTs per day; as the dose of MCTs increased up to 25 grams per day, the difference in weight loss between the experimental groups and control groups disappeared.²

Other short-term studies have found that people who eat a breakfast containing MCTs may eat less at lunch.  In one instance, people who ate yogurt combined with 20 grams of MCTs ate an average of 273 calories less at lunch than people whose yogurt contained 20 grams of LCTs.  When participants were given the MCTs along with a muffin and orange juice, however, they ate the same amount at lunch as the control group.³ In another study, participants who drank a smoothie with 25 grams of MCTs ate the same amount at lunch as the people who were given LCTs, but ate about 594 calories less throughout the remainder of the day.¹ Both of these experiments were conducted only once with small groups of people, so it isn’t really possible to apply their results to an entire population.  It will be important to conduct more studies on larger groups to see whether eating MCTs consistently results in a lower calorie intake throughout the rest of the day.

If you would like to lose weight, using MCTs in your diet might not make a big difference in your efforts. Some people have started using coconut oil instead of butter or vegetable oil because about 60% of its triglycerides are MCTs.  However, coconut oil is high in saturated fat, and research about its impact on weight loss and satiety has been mixed.⁴ To promote health and weight loss, look for sources of unsaturated fat, such as olive oil, fatty fish, and nuts.  Meet with a Registered Dietitian who can give you a meal plan that meets your calorie needs, fill up on low-calorie fruits, vegetables, whole grains, and lean protein, and get active every day!

References:

1.         Coleman H, Quinn P, Clegg ME. Medium-chain triglycerides and conjugated linoleic acids in beverage form increase satiety and reduce food intake in humans. Nutr Res. 2016;36(6):526-533. doi:10.1016/j.nutres.2016.01.004.

2.         Mumme K, 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(2):249-263. doi:10.1016/j.jand.2014.10.022.

3.         St-Onge M-P, Mayrsohn B, O’Keeffe M, Kissileff HR, Choudhury AR, Laferrère B. Impact of medium and long chain triglycerides consumption on appetite and food intake in overweight men. Eur J Clin Nutr. 2014;68(10):1134-1140. doi:10.1038/ejcn.2014.145.

4.         Coconut oil for weight loss: Does it work? Mayo Clinic. http://mayoclinic.org. Accessed July 7, 2017.

Probiotics Part 2: Effectiveness and Unknowns

Submitted by Amy Sercel MS RD CD

Edited by Marcia Bristow MS RDN CSSD CD

The idea that eating bacteria could actually improve your health might not seem logical, but that’s exactly the thought behind probiotics.  Probiotics are live bacteria that you get from food or take in pill form to gain some health benefit.^1,2 The long list of diseases that probiotics might impact includes obesity, heart disease, irritable bowel syndrome, and cancer.³

Researchers believe probiotics work by changing your microbiome, or the 39 trillion bacterial cells that live in your body, to help “good” bacteria grow and prevent “bad” bacteria from suriving.⁴ The bacteria living in your large intestine break down un-digested food components, like fiber, to form products that will be used as food for other bacteria or will be absorbed by the cells of your large intestine.  It’s thought that different types of bacteria produce compounds that affect your health in different ways.  Some might be beneficial, such as improving your immune system or supporting healthy digestion, while others may negatively impact health by promoting inflammation or causing harmful bacteria to grow.^1,5 It’s thought that consuming “good” bacteria in the form of probiotics will help more “good” bacteria grow and produce compounds that will benefit your overall health.

Unfortunately, the research on probiotics is still in its early stages. Your microbiome is unique; no one else has the same amounts or types of bacteria that you do.  Scientists have only classified about 14% of the bacteria they’ve identified so far, meaning there’s a lot more to learn about which bacteria are helpful, which bacteria are harmful, how much of each type of bacteria is best to include in a probiotic, and how different types of bacteria might interact to impact health.¹

At the same time probiotics are only sold as supplements, which do not have to be approved for safety or proven effective.⁶ Additionally, the ingredients in supplements are not regulated; a supplement may contain ingredients that are completely different from those listed on its label.  One study found that a probiotic supplement contained smaller amounts and different strains of bacteria than listed on the label, which could lead to a potentially dangerous situation if the bacteria in the probiotic turned out to be harmful.⁷

Luckily, you can impact your microbiome through your food choices.  People who eat a variety of fiber-rich fruits, vegetables, whole grains, and nuts and have diets lower in cholesterol, saturated fat, and simple carbohydrates tend to have more beneficial bacteria living in their microbiomes.² Changing your eating habits to include more fiber-rich foods can alter your microbiome within a few days.^8,9 You can also choose fermented foods that already contain beneficial bacteria, such as yogurt, kefir, sauerkraut, kimchi, tempeh, or kombucha tea.  This way, you’ll get the nutritional benefits of these whole foods and won’t have to wonder whether you are getting the right amounts or types of bacteria to keep you healthy!

References:

1.         Hemarajata P, Versalovic J. Effects of probiotics on gut microbiota: mechanisms of intestinal immunomodulation and neuromodulation. Ther Adv Gastroenterol. 2013;6(1):39-51. doi:10.1177/1756283X12459294.

2.         Ettinger G, MacDonald K, Reid G, Burton JP. The influence of the human microbiome and probiotics on cardiovascular health. Gut Microbes. 2014;5(6):719-728. doi:10.4161/19490976.2014.983775.

3.         The Role of Prebiotics and Probiotics in Human Health. J Probiotics Health. 2013;1(2):1-8. doi:10.4172/2329-8901.1000108.

4.         Sender R, Fuchs S, Milo R. Revised estimates for the number of human and bacteria cells in the body. bioRxiv. January 2016:36103. doi:10.1101/036103.

5.         Shreiner AB, Kao JY, Young VB. The gut microbiome in health and in disease. Curr Opin Gastroenterol. 2015;31(1):69-75. doi:10.1097/MOG.0000000000000139.

6.         Venugopalan V, Shriner KA, Wong-Beringer A. Regulatory Oversight and Safety of Probiotic Use. Emerg Infect Dis. 2010;16(11):1661-1665. doi:10.3201/eid1611.100574.

7.         Probiotics: In Depth. NCCIH. https://nccih.nih.gov/health/probiotics/introduction.htm. Published November 21, 2011. Accessed May 30, 2017.

8.         Turnbaugh PJ, Ridaura VK, Faith JJ, Rey FE, Knight R, Gordon JI. The Effect of Diet on the Human Gut Microbiome: A Metagenomic Analysis in Humanized Gnotobiotic Mice. Sci Transl Med. 2009;1(6):6ra14. doi:10.1126/scitranslmed.3000322.

9.         David LA, Maurice CF, Carmody RN, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014;505(7484):559-563. doi:10.1038/nature12820.