There's a scientific answer to carb's versus fats and you can determine if you naturally burn carbs easier or burn fat easier through RER testing and determining your V0
2 max. Of course most of us won't do this test, however, it is interesting. In my family, we are all unique in what we burn. I'm a carb-burner, but I do consume a balanced amount of carbs for any activity to maintain my weight.
The respiratory exchange ratio (RER) indirectly shows the muscle’s oxidative capacity to get energy. Sedentarism, exercise and physically active lifestyles modify it. For that reason, this study evaluates the associations between RER during sub-maximum ...
www.ncbi.nlm.nih.gov
I do agree with the above comments that portion size means a lot and if you eat a lot of pears, then you are driving insulin even though pears are on the healthy list. As we have all commented many times, a balanced diet is a big factor too.
As for fries, I avoid ALL fried food as the oils are not healthy, however, there are a few healthy oils such as olive oil that I'm good with.
I will carb-up a bit before a work out too, but then I've been doing that all of my life, so it's kind of a habit.
Insulin is always the strongest driver in maintaining weight, and/or weight loss. Of course, the thyroid plays a role and so does your ghrelin hormone.