Could a calorie not be a calorie after all?

[C6zo6]

"One possible footnote to this issue relates to some recent evidence on trans fats. We have seen in our studies that people who eat more trans fats seem to gain more weight, even when the total calories are the same. I was a little skeptical about that, in part because we're not quite sure we can measure calorie [intake] precisely enough. [It's hard for people to track their portion sizes to the gram, or even be sure of exactly what they're eating, especially if they ever eat out.] But in recent five-year feeding study in monkeys ??? they're animals so you can control their diets ??? the monkeys on the high-trans-fat diet gained more weight. They gained about 7% of their body weight over a five-year period, compared to the monkeys on a low-trans-fat diet, who gained about 1.5% of their body weight over five years.

So there may be something more complicated going on there. But there's not any good data [to explain why a calorie of trans fat should cause more weight gain than a calorie of something else]. It may be that on the high-trans-fat diet you're more likely to push those calories into your fat cells rather than your muscle cells ??? and muscles burn calories 24 hours a day. In the long run, that could make a difference in weight gain. But that's speculation. We're really not sure."

Reference: Which Are Worse: Calories from Carbs or Fat? - TIME

I've read a few more studies on this as well and all trans fat consumers gained more body fat...I'll have to find the other articles. But, this really makes you think that a calorie is not a calorie.

 

[Nigeepoo]

I'm guessing that the above report was based on Trans Fat Diet Induces Abdominal Obesity and Changes in Insulin Sensitivity in Monkeys

As Weight Change = (kcals eaten - kcals burned), this suggests that Industrially Produced Trans Fatty Acids (IP TFA) somehow reduce kcals burned.

I don't think that Ruminant Produced Trans Fatty Acids (RP TFA) have the same effect. See Ruminant and industrially produced trans fatty acids: health aspects noting the conflict of interest.