What unpopular/controversial opinions do you have regarding fitness/exercise/food? No BS broscience, just things that other people find harsh/do not necessarily agree with. It's better if you can back these opinions up with some sort of decent argument. I'll start, I've got a couple I wholeheartedly believe.
Unpopular opinion: Food is fuel, not therapy.
Argument - food is about giving your body what it needs, not what your brain craves. The occasional cheat is ok and mentally healthy, but the bulk of what a person consumes should be for a purpose; weight loss, weight gain, maintenence, hit macro goals, stay within calorie goals, hit micro goals, and try to fill all nutritional gaps. This is not to say you can't eat foods you enjoy and occasionally cheat, but that one should make a conscious effort to give the body what it needs with good, quality food.
Unpopular opinion: Walking is not exercise
Argument - this one is probably the most controversial of my beliefs. I do not believe walking is true exercise. Walking is good - and is a lot better than nothing, but walking does not fall into the same intensity category as things like running, cycling, swimming, weightlifting, etc. A lot of this belief stems from the quote "The human body was not designed for a sedentary lifestyle, it evolved to walk 40 miles a day and hunt saber tooth tigers". I hold that quote to be true...humans are bipedal - walking is what we evolved as our main mode of transportation. True exercise pushes the limits - walking is good and everyone should make an effort to walk more, but it is not enough on it's own to qualify a person as more than sedentary or lightly active at best.
What opinions do you have that might seem harsh or controversial?