Started lowering my carbs deliberately in the mid 80s, but went properly Low Carb around 1990 (when I started catering for myself)
Didn’t consciously increase the fat, but looking back, that inevitably happened.
During the intervening 30 yrs I have played with all sorts of different ways of eating, from 80% raw, to low GI/GL, to keto, to carnivore, to green smoothies every day, to gluten free/keto/carni, with varying (Low) carb intake.
However, I have very rarely eaten more than 50g carbs a day in that time, simply because my body handles carbs so badly that they make me feel ill.