Isn't it interesting that the world seems to press pause on life between Dec 24th and Jan 1st? Many of us still have to work, still run errands and live a semi-normal life even though the "Holidays" are here.
I hear many people say they are going to wait until after the holidays to do something. Why? Outside of being on actual vacation, is your schedule really that different this week? Of course you might have more parties or an extra day off, but you are likely working some or all of that week before Jan 1.
I'd like to encourage you to get going now on whatever it is you were putting off. Procrastinating doesn't make the task any easier. It may actually make it harder, especially if losing weight is involved. You will always have something that you'll need to work around, so treat this week as that thing and work around it.
Set your alarm a little earlier, turn off your screens, stop at the gym on the way to or from work, do whatever you need to be able to squeeze in your new task. You'll have to do the same thing next week, right? Get it over with and get started! You'll be glad you did when you get to your goal 1 week earlier than you had planned.