MCT Oil Benefits for Weight Loss, Metabolism, and Fat Burning

By Hugo Francisco de SouzaReviewed by Benedette Cuffari, M.Sc.

Introduction
What is MCT oil?
MCT structure and metabolism
Effects on energy expenditure
Effects on fat oxidation
Mechanisms of action
Considerations and limitations
Practical takeaways
Conclusions
References
Further reading

Medium-chain triglycerides are rapidly absorbed fats that increase postprandial energy expenditure, enhance fat oxidation, and stimulate ketogenesis, with modest but reproducible metabolic benefits in both lean and overweight individuals. Human evidence shows small reductions in subsequent energy intake, preserved metabolic effects in obesity, and largely neutral effects on major cholesterol markers when consumed in controlled doses.

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Introduction

As compared to long-chain triglycerides (LCTs), which are stored in adipose tissue, medium-chain triglycerides (MCTs) exploit a physiological shortcut by traveling directly to the liver, where they induce rapid thermogenesis and fat oxidation. However, while MCTs are more rapidly oxidized than LCTs, human trials show that their effects on energy expenditure and body weight are generally modest rather than dramatic.^3,5 This article discusses how MCTs have emerged as a supportive tool for weight management through their ability to increase energy expenditure, enhance fat oxidation, and modulate appetite regulation.

What is MCT oil?

MCTs are triglycerides composed of fatty acids with carbon chain lengths ranging from six to 12 atoms. MCTs are predominantly found in coconut oil, palm kernel oil, and dairy fat.^1,2 Commercial MCT oil typically contains primarily caprylic (C8:0) and capric (C10:0) acids, with little to no lauric acid (C12:0).²

As compared to long-chain triglycerides (LCTs), MCTs are rapidly hydrolyzed and oxidized, which confers a ‘functional lipid’ classification with potential applications in weight management and energy metabolism.² While historically used in clinical nutrition for treating patients with malabsorption syndromes, contemporary interest in MCTs is attributed to their capacity to enhance energy expenditure and promote fat oxidation in healthy and overweight populations.^3,5

MCT structure and metabolism

MCTs consist of a glycerol backbone esterified with medium-chain fatty acids (MCFAs), which are more water-soluble and possess a smaller molecular weight than long-chain fatty acids.^1,2

LCTs must be re-esterified into triglycerides and packaged into chylomicrons for transport through the lymphatic system. Comparatively, MCFAs are directly absorbed across the intestinal epithelium into the portal vein.^1,2

MCFAs are then bound to albumin and transported to the liver.^1,2 Although most MCFAs undergo rapid hepatic oxidation, lipidomic evidence indicates that a portion can enter systemic circulation as free medium-chain fatty acids, suggesting potential peripheral signaling effects.³

Unlike long-chain fatty acids, which rely on carnitine palmitoyltransferase-1 (CPT-1) for mitochondrial entry, MCFAs can enter mitochondria independently of the carnitine shuttle.^1,2 This property accelerates β-oxidation and promotes hepatic ketogenesis, increasing circulating β-hydroxybutyrate and acetoacetate concentrations in the postprandial period.³

Importantly, while MCTs are less readily stored than LCTs due to preferential oxidation, small amounts can still contribute to energy storage under caloric surplus conditions.¹

Effects on energy expenditure

The rapid hepatic oxidation of MCTs generates a thermogenic effect that increases postprandial energy expenditure.^3,5

In sedentary overweight individuals (BMI 25–30), ingestion of 2 g/day of MCTs for two weeks increased postprandial energy expenditure compared with LCT ingestion.^4,5 Similarly, acute MCT intake increased metabolic rate and ketone production over 5 hours in both lean individuals and individuals with obesity, with effects preserved after repeated intake.³

However, systematic evaluation of exercise performance shows that MCT supplementation does not consistently improve endurance performance or substrate utilization during prolonged exercise.⁹ Thus, thermogenic effects appear more relevant to resting and low-intensity conditions than athletic enhancement.

Effects on fat oxidation

MCTs shift substrate utilization toward fat oxidation.^3,5

Daily ingestion of 2 g of MCTs for two weeks significantly increased fat oxidation and reduced respiratory exchange ratio (RER) during low-intensity physical activity in overweight sedentary adults.⁵

Short-term ingestion also enhanced postprandial oxidation of co-ingested LCTs, as demonstrated by increased recovery of labeled CO₂ from dietary fat.⁴

Importantly, although acute fat oxidation increases are reproducible, total daily fat balance and long-term weight reduction remain modest unless combined with overall caloric control.^3,5

Mechanisms of action

Rapid hepatic delivery of MCFAs increases acetyl-CoA production, stimulating ketogenesis and transiently elevating circulating ketone bodies.³

In human trials, MCT ingestion has been shown to lower postprandial glucose concentrations, accompanied by transient increases in insulin and glucagon, suggesting improved glycemic handling.³

Decanoic acid (C10:0) acts as a ligand for GPR84.⁶ In animal models, activation of GPR84 on enteroendocrine cells increases GLP-1 secretion, improving glucose tolerance.⁶ However, direct confirmation of this pathway in humans remains limited.⁶

A systematic review and meta-analysis of controlled trials found that MCT ingestion significantly reduced subsequent ad libitum energy intake compared to LCTs, despite minimal changes in subjective appetite ratings.⁷

Considerations and limitations

Clinical responses vary according to dose, duration, metabolic status, and dietary context.

Weight loss effects associated with MCT intake are generally small and best viewed as supportive rather than primary therapeutic interventions.^3,5

A meta-analysis of randomized trials found that MCT oil did not significantly alter total cholesterol, LDL cholesterol, or HDL cholesterol overall, although triglycerides showed a small increase in some comparisons, and effects differed depending on the comparator fat.⁸

Gastrointestinal tolerance limits dosing. Acute doses above 30 g may cause gastrointestinal discomfort.⁹ Most controlled metabolic studies demonstrating benefits used lower daily doses (2–6 g) or divided doses to enhance tolerability.^4,5

Practical takeaways

Overweight sedentary individuals appear most responsive to improvements in fat oxidation and postprandial energy expenditure.⁵

Doses as low as 2 g/day for two weeks can alter substrate metabolism, while higher intakes (≈30 g/day) have been studied but carry a greater risk of gastrointestinal side effects.^4,5,9

MCTs should replace, rather than simply add to, other dietary fats to avoid unintended caloric excess.¹

Conclusions

MCTs are rapidly absorbed and oxidized lipids that increase postprandial energy expenditure, enhance fat oxidation, and stimulate ketogenesis.^3,5

Human evidence supports modest but reproducible increases in metabolic rate and fat oxidation, preservation of these effects in obesity, small reductions in subsequent energy intake, and neutral effects on major cholesterol markers under most conditions.^3,7,8

Further long-term studies are required to clarify sustained effects on body composition and to inform personalized dosing strategies.

References

1. Jadhav, H. B. & Annapure, U. S. (2022). Triglycerides of medium-chain fatty acids: a concise review. Journal of Food Science and Technology 60(8); 2143-2152. DOI: 10.1007/s13197-022-05499-w. https://pmc.ncbi.nlm.nih.gov/articles/PMC9203050/
2. Watanabe, S. & Tsujino, S. (2022). Applications of Medium-Chain Triglycerides in Foods. Frontiers in Nutrition 9. DOI: 10.3389/fnut.2022.802805. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.802805/full
3. Kanta, J. M., Lundsgaard, A., Havelund, J. F., et al. (2025). Metabolic effects of medium-chain triacylglycerol consumption are preserved in obesity. American Journal of Physiology-Endocrinology and Metabolism 328(1); E1–E20. DOI: 10.1152/ajpendo.00234.2024. https://journals.physiology.org/doi/full/10.1152/ajpendo.00234.2024
4. Nosaka, N., Tsujino, S., & Kato, K. (2022). Short-Term Ingestion of Medium-Chain Triglycerides Could Enhance Postprandial Consumption of Ingested Fat in Individuals with a Body Mass Index from 25 to Less than 30: A Randomized, Placebo-Controlled, Double-Blind Crossover Study. Nutrients 14(5); 1119. DOI: 10.3390/nu14051119. https://www.mdpi.com/2072-6643/14/5/1119
5. Tsujino, S., Nosaka, N., Sadamitsu, S., & Kato, K. (2022). Effect of Continuous Ingestion of 2 g of Medium-Chain Triglycerides on Substrate Metabolism during Low-Intensity Physical Activity. Nutrients 14(3); 536. DOI: 10.3390/nu14030536. https://www.mdpi.com/2072-6643/14/3/536
6. Nonaka, H., Ohue-Kitano, R., Masujima, Y., et al. (2022). Dietary Medium-Chain Triglyceride Decanoate Affects Glucose Homeostasis Through GPR84-Mediated GLP-1 Secretion in Mice. Frontiers in Nutrition 9. DOI: 10.3389/fnut.2022.848450. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.848450/full
7. Maher, T., & Clegg, M. E. (2020). A systematic review and meta-analysis of medium-chain triglycerides' effects on acute satiety and food intake. Critical Reviews in Food Science and Nutrition 61(4); 636-648. DOI: 10.1080/10408398.2020.1742654. https://centaur.reading.ac.uk/89667/5/CRIFSAN.%20MCT%20and%20satiety%20-%20A%20systematic%20review%2010.3.20.pdf
8. McKenzie, K. M., Lee, C. M., Mijatovic, J., et al. (2021). Medium-Chain Triglyceride Oil and Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Trials. The Journal of Nutrition 151(10); 2949-2956. DOI: 10.1093/jn/nxab220. https://www.sciencedirect.com/science/article/pii/S0022316622003662
9. Chapman-Lopez, T. J., & Koh, Y. (2022). The Effects of Medium-Chain Triglyceride Oil Supplementation on Endurance Performance and Substrate Utilization in Healthy Populations: A Systematic Review. Journal of Obesity & Metabolic Syndrome 31(3); 217–229. DOI: 10.7570/jomes22028. https://www.jomes.org/journal/view.html?doi=10.7570/jomes22028

Further Reading

• All Triglyceride Content
• Triglycerides - What are Triglycerides?
• Triglycerides - What do they do?
• Triglycerides and Disease
• Hypertriglyceridemia Treatment

Last Updated: Feb 22, 2026