Sorry to hear about that - a very unpleasant experience! As a biologist, I agree with you. I stick with a more balanced seasonal diet, slightly skewed to a higher meat, and definitely low refined sugar intake, but I don’t skip out on the fruit, veg and potatoes. Ultimately I find the most effective way I keep the weight off is simply through regular aerobic exercise and short stints of fasting (both of which induce ketosis too, just not as drastically). Weight falls right off. But if you lead a sedentary lifestyle while stuffing one’s face with unlimited butter and steaks things are not going to end well. Observe nature - energy/food acquisition is nearly always tied to energy expenditure pressures such as proof of work(hunting)/competition/survival/hunger/threat of starvation thereby creating an energy intake/expenditure balance that keeps one trim. Very few overweight wild animals out there.