How quickly you become hungry after eating not only depends on how much you ate, it also depends on what you ate.
Diet pills like Garcinia Cambogia can help, but its also important to know that some foods are more filling or satiating than others.
A recent study compared the effects of two types of fat — conjugated linoleic acid (CLA) and medium-chain triglycerides (MCTs) — on subsequent appetite and calorie intake.
Here is a detailed summary of its findings, as well as some background information.
Fat is the most calorie-rich nutrient you can find, providing 9 kcal for each gram, exceeding protein and carbs by 5 kcal.
However, fat isn’t necessarily fattening. It all depends on how much you eat, the dietary context and the type of fat.
In fact, some types of fat seem to promote the loss of excess weight. This includes conjugated linoleic acid (CLA) and medium-chain triglycerides (MCTs).
Conjugated Linoleic Acid (CLA)
CLA is a type of fat found in the milk and meat of ruminant animals, such as sheep and cows.
Supplementing with CLA is believed to benefit those who wish to lose excess fat. This is supported by a few human trials. However, the effects are small, and the clinical relevance is unclear (1, 2, 3, 4).
However, its effects on calorie intake in humans have not been investigated before.
Medium-chain Triglycerides (MCTs)
MCTs are a type of fat mainly found in palm oil, coconut oil, milk fat or supplements. They are more water-soluble and are quickly absorbed into the bloodstream after a meal.
This is likely because MCTs are a more readily available calorie source than LCT (12).
This study tested the effects of conjugated linoleic acid (CLA) and medium-chain triglycerides (MCTs) on appetite and calorie intake.
This was a randomized controlled trial examining the effects of different types of fat on appetite and calorie intake.
A total of 19 healthy men and women participated in the study. They were assigned to three test breakfasts on separate days in a random order.
All three breakfasts consisted of 250 ml of a Tesco red berries smoothie (123 kcal), providing 0.8 grams of protein and 29.8 grams of carbs (91% sugar).
Added to the smoothie were 193 kcal of fat, but the type of fat differed between the three breakfasts:
- Conjugated linoleic acid (CLA): 5 grams of CLA and 16 grams of vegetable oil.
- Medium-chain triglycerides (MCTs): 25 grams.
- Control: 22 grams of vegetable oil (unspecified).
After breakfast the participants were told to request a sandwich buffet lunch when they felt hungry enough.
The researchers measured calorie intake at the sandwich lunch. Weighed food diaries were also used to assess food intake for the rest of the day.
They also measured the time between the breakfast and self-requested lunch and assessed appetite using visual analogue scale questionnaires.
Bottom Line: This was a randomized controlled trial comparing the effects of supplementing with MCTs and CLA at breakfast on calorie intake and appetite for the rest of the day.
Finding: CLA and MCTs Reduced Calorie Intake
Supplementing with conjugated linoleic acid (CLA) or medium-chain triglycerides (MCTs) for breakfast resulted in a similar calorie intake at the lunch buffet, compared to supplementing with vegetable oil.
However, calorie intake for the rest of the day (after lunch) was significantly reduced after the participants had supplemented with CLA or MCTs for breakfast, as shown in the chart below.
Supplementing with CLA for breakfast also delayed the time until the participants requested the lunch buffet. Yet, the researchers detected no significant differences in appetite ratings.
Bottom Line: Eating CLA or MCTs at breakfast reduced calorie intake by roughly 500 kcal for the rest of the day.
The study’s design doesn’t seem to have had any major flaws, but several limitations should be mentioned.
First, the lunch buffet didn’t have a fixed time. The participants asked for it when they felt hungry enough.
Although this probably didn’t change the study’s overall findings, it probably explains why the researchers didn’t detect any between-group differences in calorie intake at lunch.
Second, calorie intake after lunch was estimated using food diaries, which are often inaccurate. However, this is unlikely to have affected the main results.
Third, five participants reported adverse digestive symptoms after supplementing with MCTs. This discomfort might have reduced their appetite and calorie intake later in the day.
In comparison, only one participant reported digestive discomfort after supplementing with CLA, and there were no adverse symptoms after consuming the control breakfast.
Finally, the calorie content of the two test lipids did not match. The amount of CLA used was 5 grams, whereas the dose of MCTs was 25 grams. As a result, the study didn’t provide an equal comparison of CLA and MCTs.
Bottom Line: The study didn’t have any major limitations to its design. However, there are some limitations to how its results can be interpreted.
Summary and Real-Life Application
This study showed that supplementing with CLA or MCTs for breakfast significantly reduced calorie intake for the rest of the day, compared to vegetable oil.
The reduction in calorie intake amounted to approximately 500 kcal. This calorie reduction should result in considerable weight loss over time, but it is unclear to what extent these effects are sustained when CLA or MCTs are taken regularly.