If you want to lose weight, reduce carbs. If you want to gain weight, consume more carbs. If you want to maintain weight, find a proper balance of carbs, proteins, and fats.
Avoid processed food as much as possible.
There's a difference between 2 spoons of sugar in your cups of coffee / tea, and 10.
Also, plain sugar is different than high-fructose corn syrup.
I think sugar can be used as a stimulant to boost brain function, muscle explosiveness, and for growth / muscle in general. Just controlling its intake when so readily available is the hard part. I did keto for a while but found a hard time gaining weight, with sugar it just makes it so much easier. When you reach desired weight can reduce sugar intake.
The synthetic stuff like HFCS will always be worse. Yeah you gotta read labels but how many people do not? Still there are tons of horseshit on the shelves.
Sugar activates the same brain receptors as cocaine, it's addicting for sure. Sitting down all day doesn't help. I tried all the diets out there, I've always just done the best I think when I balanced it all out in terms of sugar, protein, and fat.
1-2 hours a day of exercise, even if it's just walking is mandatory though.
Half-life.