19 was 109lbs, gained 20 pounds in 7 months without diet or exercise change, why so?

recently i have noticed that i gained 20 pounds in the past 7 months. i was always thin and could eat whatever i wanted and it wouldnt have any effect on me. since i noticed the weight gain i have been eating ALOT better and dieting and exercising more but i have even gained weight and its getting frustrating. however, i have also noticed that i have less energy and sleep alot more; when i eat, i get bloated to the point i look pregnant; and havent been going to the bathroom as much. what could potentially be causing this and why isn't anything working?

has anything changed in your lifestyle in the last 7 months? A new job? studying more (= less active)? Stopped playing sports? Under stress? (eating without acknowledging it)

When I went to University, I gained 20 pounds in about 6 months - I wasen't exercising as much (I left a dance troupe I was a part of so I could have more time to study) and was working a job in a bakery and got to eat lots of yummy free lunches that were high in fat and calories. It's been 5 years, and I'm still trying to work off the weight.

Maybe you're under some stress. It can change your energy levels

I am 23 and went through t he same thing a few months ago. Weight gain, bloating, etc. Have your doctor test your thyroid to be sure that it;s not under active. If nothing, then it's probably just stress related. I never found a real answer to my problem other than that. Also, I found it very hard to lose it after.

Talk to your doctor. It might be cushing's syndrome / disease. It causes rapid weight gain, depression, fatigue, etc. The biggest thing is talking to your doctor. Write everything down before you go for your visit. How you feel, when you started to notice it, any changes in skin type of areas which appear to have collect more weight, changed emotions, etc..