@reddragon4444 Age 56, my overall POV, reinforced by my lean adult weight fluctuating from 155 to 205+:
CICO. Period.
Studies done with carb overfeeding seem to demonstrate a greatly increased resting EE, and a lot smaller contribution to denovo lipogensis than is often quoted. In theory it might be slightly easier to absorb a small surplus of carbs without gaining fat if you are already eating relatively low fat, than it would be to absorb a surplus on a high fat diet.
Other research showed a slightly larger decrease in body fat by cutting dietary fat over an identical calorie value of dietary carbs when in an overall deficit.
That said, these are VERY modest effects compared to overall CICO. Almost all the negatives associated with this or that diet only appear in individuals at higher BMI. Eating at maintenance with a moderate bodyfat % almost any diet high enough in protein and micronutrients will be "healthy".
Other than that I am a firm believer that there is no such thing as junk food, but there is such a thing as an appropriate portion size for a given food item. For nutritionally weak foods, that serving size might be very small indeed. If you have to cut too much whole food items to make way for processed or luxury foods, you're going to see and feel it at some point.
The whole sugar obesity insulin link fell apart back when Attia and Taubes own research disproved the theory. US per capita sugar consumption peaked in 1972.