I heard about keto diet and tried severely limiting sugar and other carbs intake. I instantly felt better and lost 6kg in two months. Sticking to the new diet was pretty easy. Now after 6 months I have constant headache, painkillers don't work, constantly tired and no further weight loss whatsoever. Every test was ok, sugar perfect, just insulin in upper bound of range. Limiting sugar is not panacea. Sometimes it works, sometimes it doesn't.