without eating anthing much how do people become fat

Some people like me are lucky in the sense that they can eat all they want and still maintain the same basic weight. People tell me it is because of a 'higher metabolism.' Or, more simply, the ability to burn fat. I'm not doctor, but what thing I know for sure is that there are a lot of factors besides eating that contribute to a persons weight. Personally, I think the one I hear the most about is a hormone imbalance. I think the best thing for your friend to do is seek medical advice and possibly the problem can be resolved medically.

Well, your friend may have a medical problem. Or it could be that his body has entered a "starvation mode" and is actually burning less fat as it senses that it is not getting a sufficient supply of food to work at a healthy level. If this has been going on for sometime, your friend should go see a doctor.

It sounds as if he needs more exercise. People who don't get any exercise won't burn calories and will feel restless and tired. He might start out slow and work up to a more vigorous exercise but first he needs to see a doctor to make sure there is no medical reason for it.

Maybe your friend is eating the wrong things, and maybe he is not eating enough. It is essential to get all the necessary nutrients either through food or suplements. It does not sound like he gets enough energy from his food. he should focus on getting enough proteins and good fat (like from extra virgin olive oil, nuts, fish), and eating less of sugar, wheet and potatoes, pasta and rice. he needs to eat small meals often to keep his blood sugar levels in balance. If he starts eating small meals four to five times a day his metabolism should get better. If not I recomend he see a nutritionist. maybe he has a hormone imbalance. That would make loosing weight without help very difficult. I was on a diet for 6 months and gained weight - my partner lost 20 kg. It was impossible for me to loose weight due to a hormone imbalance. It may be well worth checking this out.

I think your friend should go to the doctor for some tests. It's possible they could have a thyroid condition or diabetes. Hopefully not, but it's always worth getting these things checked.