MCT Oil for Weight Loss
MCT oil shows modest potential for weight loss when incorporated into a calorie-controlled diet, but the evidence is limited and the effects are small—expect approximately 1-2 kg additional weight loss over 16 weeks compared to other oils. 1
Evidence Quality and Context
The available evidence for MCT oil specifically for weight loss is surprisingly weak:
Only one high-quality randomized controlled trial directly examined MCT oil for weight loss, showing that 18-24 g/day of MCT oil resulted in 1.67 kg greater weight loss compared to olive oil over 16 weeks in overweight adults (BMI ~30) 1
Coconut oil cannot be substituted for MCT oil for weight loss purposes, as coconut oil contains only 50-60% MCTs versus 100% in pure MCT oil, and research confirms coconut oil lacks the satiating properties of MCT oil 2, 3, 4
A 2017 systematic review concluded there is insufficient consistent evidence on coconut oil, satiety, and weight loss, with media claims primarily based on MCT oil studies being inappropriately extrapolated 3
Mechanism and Metabolic Effects
MCT oil may support weight loss through several pathways:
Enhanced thermogenesis: MCTs increase energy expenditure by 6-9% during infusion compared to baseline, with fat oxidation increasing 15-24% 5
Superior satiety: MCT oil significantly reduces food intake at subsequent meals and increases fullness ratings compared to both coconut oil and control oils 4
Improved body composition: The 16-week trial showed trends toward greater loss of fat mass (p=0.071) and trunk fat mass (p=0.10), with lower endpoint trunk fat, total fat mass, and intraabdominal adipose tissue compared to olive oil 1
Clinical Guideline Context
Important caveat: The primary guideline recommendations for MCT oil focus on clinical nutrition support, not weight loss:
The American College of Cardiology recommends MCT oil only for patients who need extra calories on very-low-fat diets (10-15% of calories) for severe hypertriglyceridemia management, specifically stating to "add MCT oil gradually" 5
ESPEN guidelines support MCT use in critically ill patients and those with malabsorption, not for weight loss in healthy individuals 5
Practical Recommendations
If you choose to recommend MCT oil for weight loss:
Dosage: Use 18-24 g/day (approximately 1.5-2 tablespoons) as part of a structured weight-loss program 1
Integration: Replace other dietary fats rather than adding MCT oil on top of current intake, as the benefit comes from fat quality changes, not increased calories 1
Gradual introduction: Start with lower volumes (5-10 g/day) and increase gradually to minimize gastrointestinal side effects including abdominal pain, nausea, and diarrhea 6
Realistic expectations: Anticipate modest additional weight loss of 1-2 kg over 4 months beyond standard dietary interventions 1
Critical Limitations
Major concerns that should temper enthusiasm:
Single supporting study: Only one RCT directly supports MCT oil for weight loss in otherwise healthy overweight individuals 1
No long-term data: The longest trial was only 16 weeks; sustainability and long-term safety for weight loss purposes remain unknown 3
Potential adverse effects: MCTs can increase total homocysteine levels (a cardiovascular risk marker), though they may improve other lipid parameters 7
Cost-effectiveness: MCT oil is significantly more expensive than conventional dietary modifications with stronger evidence bases 3
Bottom Line Algorithm
For patients asking about MCT oil for weight loss:
First-line approach: Emphasize evidence-based dietary patterns (reduced carbohydrates, increased protein, fiber-rich whole grains) which show more robust weight loss effects 5
If patient insists on MCT oil: Can be incorporated at 18-24 g/day as a fat replacement (not addition) within a structured weight-loss program, with realistic expectations of modest benefit 1
Monitor for: Gastrointestinal tolerance, and consider discontinuation if significant GI distress occurs 6
Do not recommend: Coconut oil as a substitute, as it lacks equivalent effects 4