Published March 10, 2014
Since you're pretty much fluent in diet-speak, you know that consuming too much fat can lead to weight gain.
But get this: According to new Swedish research, it's not just about how much fat your diet includes--it's about what type of fat you're taking in. The study, published in the journal Diabetes, found that consuming saturated fat actually builds more body fat and less muscle than consuming polyunsaturated fat.
For the study, researchers instructed 39 young adults to eat 750 calories' worth of muffins every day for seven weeks--in addition to their regular diets. The goal was to have the participants gain roughly 3 percent of their starting body weight by the study's end. But here's the clincher: The scientists gave half of the group muffins made with palm oil, a saturated fat, and they gave the other half muffins made with sunflower oil, a polyunsaturated fat.
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Both groups gained the same amount of weight. But interestingly, those who ate the muffins made with saturated fat gained more fat overall, specifically in their livers and abdomens. What's more, they also gained three times less muscle mass than the polyunsaturated group, which is a bummer because when it comes to weight gain, muscle mass is what you want. So, why the difference?
Researchers say that saturated fats may cause your body to produce more abdominal fat--also known as visceral fat (find out why it's so important to lose belly fat in particular). Polyunsaturated fats, on the other hand, may actually regulate the storage of visceral fat in your body.
Now, we can practically hear your next question: If both groups gained the same amount of weight, then why, exactly, does the fat gain even matter? It all comes down to your metabolism.
See, both liver fat and visceral fat disrupt your metabolism more than other fats do, say the researchers. And that's dangerous because your metabolism keeps your body running smoothly, meaning if you mess with its flow now, you could end up gaining more weight later on. Just another reason to limit your intake of saturated fats.