Is losing 15lbs in 6 weeks realistic?

Don't worry so much about the number. Eat at a deficit and exercise, you'll see results in the mirror in June.

Only if you are obese, which according to your ticker you are not. I would probably aim for 4-6 lbs instead.

Not realistic. With 20lbs to lose, you'd be aiming for more 0.5-1lb/week loss. If you are consistent, you could lose 3-6lbs in those 6 weeks.

but it sounds more like a body composition thing versus the actual scale number. If you aren't already doing strength training, it'd be a good time to start. You won't see major changes in 6 weeks, but it'd be better than just doing cardio and losing those lbs and no inches.

maybe if you ate exactly 1200 calories every day haha but even then i don't know. I wouldn't want to try it

I recommend just doing your best and not setting goals that may be unrealistic for your current size. When we set expectations and then don't hit them, we tend to get discouraged which causes us to lose focus. Do your best each day and let the scale do whatever it does.

But, hey, if you can average 2 lb loss per week for 6 weeks, more power to you

and I'm not saying this is the healthiest way to do it....and any loss may not be sustainable....but here's your outline for max weight loss over the next 6 weeks....

nutrition:

weeks 1 and 2 ... eat only veggies and drink only water. You can have as many veggies as you want, cooked or raw. Get A LOT of veggies. After a few days, your body will adjust. You will have to deal with boredom, sure, but you will be satiated.

weeks 3-6..... same as weeks 1 and 2, but also add 8 ounces of chicken breast or turkey breast per day.

workout:

sprint interval training 3x per week (no more than this, and don't add to the sprint interval training on those days). You're going to do 8-12 intervals that look like this. Go outside. Do a 15 second sprint where you're going all out, pushing from your butt. If you do the sprint correctly, you should be gassed within 15 seconds. If you're not pushing hard enough, you're not doing the sprint correctly. The idea is to get to near max HR for proper HIIT. After doing the sprint, do a bodyweight exercise (i.e., pushups, air squats, burpees, step ups, plank, etc.) Then rest until your HR drops below 130. Then do another interval. So you're going to do 8-12 intervals that look like this... 15 second sprint + bodyweight exercise + rest. Rest will be the longest part of each interval, and that's the way HIIT works. That's the entire workout. Do not do this on back to back days. Oh, and before you start the workout, stretch your hips, quads, hamstrings, calves and Achilles (the downward dog position where you peddle your feet is great for calves and Achilles).

You really don't need to do any other workout than the sprint interval training. but if you want to add a moderate paced cardio workout like jogging or biking or swimming 1-2 days per week, that's fine. Not necessary though....and make sure you're getting at least 2 rest days per week.

I'm down 15lbs in almost 4 weeks.

sure, just work your *kitten* off. Eat at a deficit. you'll lose. but realistically you'll probably loose closer to 10.

INSANITY

In order to lose 2lbs a week, you'd have to be at a 1000 cal deficit a day. Seeing as you don't have that much to lose..that kind of deficit isn't realistic nor healthy. And if you actually managed to stick to something like that, 6 weeks is enough time to end up making yourself sick.

Granted, you could lose a lot of water weight but it's not going to affect your appearance in the way you think those 15lbs off is going to because of how fast you are trying to do it. And there is a high chance that you'll just end up gaining it back anyways, if you don't end up going on a binge and gaining even more.