I feel so, so physically and mentally tired most days almost all days (without caffeine) and I always thought it was from the lack of a good 8+ hours of sleep, the fact that I can't even sleep for a full 8 hours straight through at least, and just staring at screens on my phone or video games systems before immediately going to bed. I thought these things were making me so sluggish in the morning and the day, but now that I'm seriously looking at my eating habits in an effort to lose weight, I find that...I'm barely eating 1,000 calories a day in food. The recommended daily calorie intake is about 2,000 calories a day, and I think 1,000 calories is almost at the starvation point. Granted, I also lightly exercise daily by taking walks around my work building just to keep myself moving. Yet, I never really noticed the feeling of hunger? Sometimes I do skip breakfast, especially if I wake up late, and will eat a few things for lunch and really portion control my dinner (or skip dinner altogether because I just don't feel hungry), and I'm thinking that it's the lack of proper caloric intake that may contribute to my state of exhaustion every day. I don't really feel pangs of hunger probably because my body is so used to it, but I'm afraid of eating more because I need to lose some of the weight that I have. So I think...getting more sleep might help take away some of that tiredness? 8 hours simply isn't enough: I feel better when I have a good 9-10 hour sleep. I just want to feel energized and motivated again like I was in highschool/college without relying on coffee and caffeine.
It gets a lot more specific than that, 1,000 calories is ok for some people and not for others as a weight loss strategy. It's definitely not the starvation point for anyone though, that's more like 400. In general though yes eating a small amount of calories like that will destroy your energy levels because your body won't allow all the energy to be released at once like with a normal caloric amount, it holds a lot back from you trying to extend it over time not knowing when it's going to get more food. That's why starvation diets don't work, it just makes the body hold onto calories longer. Eating a healthy 2,000 calories is better than trying to force weight loss with only 1,000 for long-term success. The sleep thing is actually based more on when in your REM cycle you wake up than the amount of hours slept. If you wake up in the deepest part of sleep you're always going to be tired no matter how long you slept, and if you wake up in the lightest part you'll often feel energetic even if you only slept a few hours. If 9-10 works for you then do that, overall 7 hours is considered the ideal amount for most people.
You might also try putting the electronics away a half hour or more before bed to help your brain switch off. Do something else like read a book or maybe tidy up your room/apartment. If you don't feel hungry than you likely are simply not hungry. Though talking to a dietrician would be beneficial just to make sure you are taking in enough fuel for your activity level.
