It's so weird. This week I kinda cheated the whole week on sugar and all my headaches disapeared and I lost 5 pounds only in this week (I'm sure of it). I was eating about 2000- 2500 calories I think when I usually eat appr. 1300-1500 calories. I got periods where my sugar craving are really really intense and in these times, all I can eat is sugar, I'm thinking about sugary foods all the time and I simply can't say no to myself (gonna work on that). I'll try not to cheat again but what about my weight loss ? Why did I lose weight ? With this increase in calories and sugar all of my fatigue and headache disapeared also, so this could be a sign of sugar addiction. Or maybe I wasn't eating enough calories, my metabolism wasn't fully efficient but I can't possibly have a daily range of appr. 2000 calories for my metabolism to work in the fullest. That's so weird. Has this ever happen to one of you ?

Depending on the amount of activity you do, you probably aren't eating enough. If you normally feel fatigued when you eat less then I would say this is the problem.

What I would do is try to keep the calorie intake up for the next week and see if you keep losing and feeling better. Then you'll know you weren't eating enough.