How can i lose 15 pounds during the holidays?

First of all, it would take you about ten weeks to lose 15 pounds on a strictly-followed regime. Secondly, why pick THE hardest time of the year to decide you NEED to lose weight, why not make your goal to maintain, then start actually cutting back on the crap and increasing your exercise AFTER the holidays?
Are you trying to punish yourself?

EDIT:
It’s unhealthy and impossible. Tell your dad I said he’s an asshat (but I actually think your I’m-obeying-Daddy story is bull$hit).
References :

Resistance training is one of the best methods to raise your metabolism and lose weight fast. One of the most common views which is completely wrong is that weight training is only for people who are interested in getting big muscles and a huge strong body. Women always overlook weight training because they don’t want to build muscles and just want to focus on losing weight. The truth is that resistance training is essential if you want to burn fat fast. In fact it is so powerful that you will even burn calories in your sleep or while laying down watching TV! Here’s how resistance training works.

When your muscles face resistance, they break down and need to be rebuilt by your body. This is why you feel sore all over after you’ve done a bit of weight lifting or resistance training. The process of rebuilding muscles takes a lot of energy and happens 24 hours a day, which is why your body will constantly be burning fat even while you sleep.

Getting that toned and sculpted look that many famous actors have is accomplished by resistance training. If you want to lose the flab in your body and make it look lean, toned, and perfectly sculpted, then you will undoubtedly need to do some form of resistance training.

The best thing about resistance training is that all you need is about 60 minutes a week of it to get the body you want. If you’re a very busy person and don’t have time to go gym for hours a day, then you will still be able to get the weight loss benefits by doing just a few minutes of weight training every two days or so. But resistance training doesn’t just help you lose weight, here are some other benefits:

.Boosted metabolism rate: because your body will need a lot more energy (calories) to rebuild the muscles you’ve broken down, your metabolism rate will greatly increase. (For those of you not familiar with the word "metabolism", it’s basically the amount of energy your body needs to keep you alive and well.)
.Stronger bones and muscle: carrying things won’t be as difficult as it used to be and your chances of getting a bone disease will greatly decrease.
.Toned and sculpted look: you will get the lean and fit body (without the flab) that you’ve always wanted.
.Healthier and stronger body: overall you will just feel a lot healthier and stronger. This will boost your self-esteem, confidence, and will open up a lot of new opportunities in your life.
The important thing to understand is that incorporating resistance training in your weight loss plan is essential if you want to lose weight AND get the lean body you’ve wanted for so long.

Now that you know the two main methods of burning calories to create a deficit, here is one of the more popular ways of losing weight.
References :